JP2022027885A - Eyepieces for augmented reality display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide eyepiece waveguides for an augmented reality display system.

SOLUTION: An eyepiece waveguide for an augmented reality display system may include an optically transmissive substrate, an input coupling grating (ICG) region, a multi-directional pupil expander (MPE) region, and an exit pupil expander (EPE) region. The ICG region may receive an input beam of light and couple the input beam into the substrate as a guided beam. The MPE region may include a plurality of diffractive features which exhibit periodicity along at least a first axis of periodicity and a second axis of periodicity. The MPE region may be positioned to receive the guided beam from the ICG region and to diffract it in a plurality of directions to create a plurality of diffracted beams. The EPE region may be positioned to receive one or more of the diffracted beams from the MPE region and to out-couple them from the optically transmissive substrate as output beams.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

(Incorporation by reference of all priority applications)
This application was filed on December 15, 2017, entitled "EYEPIECES FOR AUGMENTED REALITY DISPLAY SYSTEM", US Provisional Patent Application No. 62/599663, filed on December 20, 2017, "EYEPIECES FOR AUXMENTED". US Provisional Patent Application No. 62/608555 entitled "REALITY DISPLAY SYSTEM" and US Provisional Patent Application No. 62 / entitled "EYEPIECES FOR AUGMENTED REALITY DISPLAY SYSTEM" filed on January 22, 2018. Claim the priority of No. 62465. Any application in the application data sheet in which a foreign or domestic priority claim is identified above and / or is filed with this application is incorporated herein by reference under 37CFR 1.57. ..

(Field)
The present disclosure relates to eyepieces for virtual reality, augmented reality, and mixed reality systems.

(Explanation of related applications)
Modern computing and display technologies are driving the development of virtual reality, augmented reality, and mixed reality systems. A virtual reality or "VR" system creates a simulated environment for the user to experience. This can be done by presenting computer-generated image data to the user through a head-mounted display. The image data creates a sensory experience that immerses the user in a simulated environment. Virtual reality scenarios typically involve the presentation of computer-generated image data only, rather than also including real-world image data.

Augmented reality systems generally complement the real-world environment with simulated elements. For example, an augmented reality or "AR" system may provide the user with a view of the surrounding real-world environment via a head-mounted display. However, computer-generated image data can also be presented on the display to improve the real-world environment. The computer-generated image data may include elements that are contextually relevant to the real world environment. Such elements can include simulated text, images, objects, and the like. A mixed reality or "MR" system is a type of AR system that also introduces simulated objects into a real-world environment, but these objects are typically of further interaction. Characterized by degree. Simulated elements can often be bidirectional in real time.

FIG. 1 depicts an exemplary AR / MR scene 1 in which the user sees a real-world park setting 6 featuring people, trees, buildings in the background, and a concrete platform 20. In addition to these items, computer-generated image data is also presented to the user. Computer-generated image data can include, for example, a robot image 10 standing on a real-world platform 20 and a flying cartoon-like avatar character 2 that looks like anthropomorphic bumblebees. 2 and 10 do not actually exist in the real world environment.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. An ICG region configured to receive an input beam of light and couple the input beam into the substrate as a guided beam, and a multidirectional pupil expander (MPE) region formed on or within the substrate. Thus, the MPE region comprises a plurality of diffraction features exhibiting periodicity along at least a first periodic axis and a second periodic axis, receiving a guided beam from the ICG region and diffracting it in multiple directions. The MPE region, which is positioned to create multiple diffracted beams, and the exit pupil expander (EPE) region, which is formed on or within the substrate, of one or more of the diffracted beams. It comprises an EPE region that receives from the MPE region and is positioned to externally couple them as an output beam from an optically transmissive substrate.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is configured to receive a set of input beams of light and combine the set of input beams into a substrate as a set of guided beams, the set of guided beams being at least partially the eyepiece lens waveguide. Associated with the set of k-vectors in k-space within the k-spatial ring associated with, the k-spatial ring is the region within k-space associated with guided propagation within the eyepiece lens waveguide. Corresponding to the ICG region and the multidirectional pupil expander (MPE) region formed on or within the substrate, the MPE region is positioned to receive a set of guided beams from the ICG region, at least. It is configured to diffract a set of guided beams so as to create three sets of diffracted beams, the set of diffracted beams being at least partially within the k-spatial ring at three different angle locations. An MPE region associated with at least three sets of k-vectors to be centered and an ejection pupil expander (EPE) region formed on or within a substrate, one of a set of diffracted beams. It comprises an EPE region that receives one from the MPE region and is positioned to externally couple them as an output beam from an optically transmissive substrate.

In some embodiments, the eyepiece waveguide for the augmented reality display system is an input coupling region for receiving the input beam of light associated with the image, and the input beam of light is associated. An input coupling region with a pupil, a multidirectional pupil expander (MPE) region configured to expand the pupil in at least three directions, and an output beam of light associated with the image. It has an emission area.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is to receive a set of input beams of light, that set of input beams is associated with a set of k-vectors in k-space, and that a first set of guided beams and a first set of guided beams. By diffracting a set of input beams so as to create a set of non-diffractive beams, the first set of guided beams is in the k-spatial ring associated with the eyepiece waveguide. Corresponding to the parallel movement subset of the k-vector, the first set of non-diffraction beams corresponds to the parallel movement subset of the k-vector, which is outside the k-space ring, and the k-space ring corresponds to the eyepiece waveguide. Corresponding to the region in the k-space associated with the guided propagation in the tube, and to create a separate set of second guided beams and a separate set of second non-diffraction beams of the input beam. To diffract the set, the second set of guided beams corresponds to a parallel moving subset of k-vectors within the k-space ring, and the second set of non-diffraction beams corresponds to the k-space. An ICG region and a first pupil expander region formed on or in the substrate, configured to correspond to a parallel movement subset of k-vectors outside the ring, the first. Formed on or in a substrate with a first pupil expander region that is positioned to receive a set of guided beams of 1 from the ICG region and is configured to replicate them as a set of first duplicate beams. A second pupil expander region, positioned to receive a second set of guided beams from the ICG region and configured to replicate them as a second set of duplicate beams. The pupil expander region and the exit region formed on or within the substrate, the exit region is positioned to receive a set of first and second duplicate beams, which are externally coupled as output beams. The output beam comprises an exit area that represents a complete set of input beams.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is to receive a set of input beams of light, the set of input beams is associated with a set of k-vectors that form a field of view (FOV) shape in k-space, and the FOV shape is. The k-spatial ring has a first dimension in the k-space that is greater than the width of the k-spatial ring associated with the eyepiece waveguide, and the k-spatial ring is associated with the guided propagation within the eyepiece lens waveguide. Corresponding to regions in space, coupling them as guided beams into the substrate, and moving the FOV shape in parallel to both the first and second positions in the k-space ring. Thus, in the first position, part of the FOV shape is outside the k-space ring and only the first subpart of the FOV shape is the k-space ring. Inside, at the second position, part of the FOV shape is outside the k-space ring, and only the second subpart of the FOV shape is inside the k-space ring. The complete FOV shape is reassembled into the ICG region and the plurality of pupil expander regions formed on or within the substrate, the first and second subparts of the FOV shape. It comprises a plurality of pupil expander regions positioned to diffract the guided beam so as to move parallel to a third position in the k-spatial ring.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is configured to receive a set of input beams of optics and combine the set of input beams into a substrate as a set of guided beams, where the set of input beams is a set of k-vectors in k-space. Associated with, the set of k-vectors has a first dimension in k-space that is greater than the width of the k-spatial ring associated with the eyepiece lens waveguide, and the k-spatial ring is the eyepiece guide. An ICG region corresponding to a region in k-space associated with guided propagation in a waveguide and a plurality of pupil expander regions formed on or within a substrate, collectively, ICG the guided beam. Multiple pupil expander regions that receive from the region and are positioned to diffract them to create a set of duplicate beams, and an exit region that is formed on or within the substrate and receives the duplicate beams. The duplicate beam is provided from an optically transmissive substrate with an exit region positioned to externally couple as a set of output beams representing a complete set of input beams.

式中、ｎ_２は、光学的に透過性の基板の屈折率であって、ｎ_１は、光学的に透過性の基板
を囲繞する媒体の屈折率であって、ωは、光の入力ビームの角周波数であって、ｃは、光の速さの定数である、ＩＣＧ領域と、基板上または内に形成される、複数の瞳エクスパンダ領域であって、集合的に、ビームをＩＣＧ領域から受け取り、複製ビームのセットを作成するように、それらを回折するように位置付けられる、複数の瞳エクスパンダ領域と、基板上または内に形成される、出射領域であって、複製ビームを受け取り、複製ビームを、光学的に透過性の基板から、完全入力画像を表す、出力ビームのセットとして外部結合するように位置付けられる、出射領域とを備える。 In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling grating (ICG) region formed on or within the substrate. The ICG region comprises a diffraction grating configured to diffract a set of input beams of light corresponding to an input image to multiple diffraction orders, the grating having a period Λ that satisfies:

In the equation, n ₂ is the refractive index of the optically transmissive substrate, n ₁ is the refractive index of the medium surrounding the optically transmissive substrate, and ω is the input beam of light. The angular frequency of, c is the ICG region, which is a constant of the speed of light, and a plurality of pupil expander regions formed on or in the substrate, and collectively, the beam is in the ICG region. A plurality of optical expander regions that receive from and are positioned to diffract them to create a set of duplicate beams, and an exit region that is formed on or within the substrate and receives the duplicate beams. The duplicate beam is provided from an optically transmissive substrate with an exit region positioned to be externally coupled as a set of output beams representing a complete input image.

を満たす周期Λを有し、ｎ _２ は、前記光学的に透過性の基板の屈折率であり、ｎ _１ は、前記光学的に透過性の基板を囲繞する媒体の屈折率であり、ωは、前記光の入力ビームの角周波数であり、ｃは、光の速さの定数である、ＩＣＧ領域と、
前記基板上または前記基板内に形成される複数の瞳エクスパンダ領域であって、前記複数の瞳エクスパンダ領域は、集合的に、前記ビームを前記ＩＣＧ領域から受け取り、複製ビームのセットを作成するように、それらを回折するように位置付けられる、複数の瞳エクスパンダ領域と、
前記基板上または前記基板内に形成される出射領域であって、前記出射領域は、前記複製ビームを受け取り、前記複製ビームを、前記光学的に透過性の基板から、前記完全入力画像を表す出力ビームのセットとして外部結合するように位置付けられる、出射領域と
を備える、接眼レンズ導波管。
（項目６４）
拡張現実ディスプレイシステムのための接眼レンズ導波管であって、前記接眼レンズ導波管は、
第１の表面および第２の表面を有する光学的に透過性の基板と、
前記基板の表面のうちの１つ上または前記基板の表面のうちの１つ内に形成される第１の入力結合格子（ＩＣＧ）領域であって、前記第１のＩＣＧ領域は、光の入力ビームを受け取り、前記入力ビームを前記基板の中に誘導ビームとして結合するように構成される、第１のＩＣＧ領域と、
前記基板の第１の表面上または前記基板の第１の表面内に形成される多指向性瞳エクスパンダ（ＭＰＥ）領域であって、前記ＭＰＥ領域は、少なくとも第１の周期性軸および第２の周期性軸に沿って周期性を呈する複数の回折特徴を備え、前記ＭＰＥ領域は、前記誘導ビームを前記第１のＩＣＧ領域から受け取り、それを複数の方向に回折し、複数の回折ビームを作成するように位置付けられる、ＭＰＥ領域と、
前記基板の第２の表面上または前記基板の第２の表面内に形成される射出瞳エクスパンダ（ＥＰＥ）領域であって、前記ＥＰＥ領域は、前記ＭＰＥ領域に重複し、前記ＥＰＥ領域は、前記回折ビームのうちの１つ以上のものを前記光学的に透過性の基板から出力ビームとして外部結合するように構成される、ＥＰＥ領域と
を備える、接眼レンズ導波管。 In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate having a first surface and a second surface, and one of the surfaces of the substrate. A first input coupling lattice (ICG) region formed above or within, configured to receive an input beam of light and couple the input beam into a substrate as a guided beam. An ICG region and a multidirectional pupil expander (MPE) region formed on or within a first surface of a substrate, wherein the MPE region is at least a first periodic axis and a second periodic axis. With multiple diffraction features that exhibit periodicity along the MPE region, which is positioned to receive the guided beam from the first ICG region, diffract it in multiple directions, and create multiple diffracted beams. An exit pupil expander (EPE) region formed on or within a second surface of the substrate, the EPE region overlapping the MPE region and optically illuminating one or more of the diffracted beams. It is provided with an EPE region configured to be externally coupled as an output beam from a transmissive substrate.
The present specification also provides, for example, the following items.
(Item 1)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling grid (ICG) region formed on or within the substrate such that the ICG region receives an input beam of light and couples the input beam into the substrate as a guided beam. The ICG area and
A multidirectional pupil expander (MPE) region formed on or within the substrate, wherein the MPE region is periodic along at least a first periodic axis and a second periodic axis. With a plurality of diffraction features, the MPE region is positioned to receive the guided beam from the ICG region, diffract it in multiple directions, and create a plurality of diffracted beams.
An exit pupil expander (EPE) region formed on or within the substrate, wherein the EPE region receives one or more of the diffracted beams from the MPE region and receives them from the optical region. With the EPE region, which is positioned to externally couple as an output beam from a transparent substrate.
Equipped with an eyepiece waveguide.
(Item 2)
The eyepiece waveguide according to item 1, wherein the MPE region comprises a two-dimensional lattice pattern with distinct diffraction features.
(Item 3)
The eyepiece waveguide according to item 1, wherein the MPE region includes a cross grid.
(Item 4)
The eyepiece waveguide according to item 1, wherein the MPE region is configured to create the diffracted beam by diffracting a part of the power of the guided beam from the ICG region in at least three directions. ..
(Item 5)
Item 4. The eyepiece waveguide according to item 4, wherein one of the three directions corresponds to a zero-order diffraction beam.
(Item 6)
Item 4. The eyepiece waveguide according to item 4, wherein two or more of the three directions correspond to a primary diffraction beam.
(Item 7)
The eyepiece waveguide according to item 4, wherein the three directions are angularly separated by at least 45 degrees.
(Item 8)
The eyepiece waveguide according to item 4, wherein the MPE region and the EPE region do not overlap, and only one of the three directions of the diffracted beam intersects the EPE region.
(Item 9)
The eyepiece waveguide according to item 4, wherein one of the three directions corresponds to the direction from the ICG region to the MPE region.
(Item 10)
The eyepiece waveguide according to item 4, wherein the MPE region is configured to create the diffracted beam by diffracting a portion of the power of the guided beam from the ICG region in at least four directions. ..
(Item 11)
The eyepiece waveguide according to item 10, wherein the four directions are angularly separated by at least 45 degrees.
(Item 12)
The MPE region is further again a diffracted beam by diffracting a diffracted beam that is still propagating within the MPE region after being initially diffracted at a plurality of dispersion locations in the same plurality of directions. The eyepiece waveguide according to item 1, which is configured to increase the number of.
(Item 13)
The eyepiece waveguide according to item 12, wherein only a subset of the diffracted beams propagate toward the EPE region.
(Item 14)
13. The eyepiece waveguide according to item 13, wherein the EPE region is positioned to receive only one of the diffracted beams propagating in one of the plurality of directions.
(Item 15)
The eyepiece waveguide according to item 14, wherein the diffracted beam propagating toward the EPE region has a non-uniform spacing.
(Item 16)
The eyepiece waveguide according to item 1, wherein some of the diffraction features in the MPE region have a diffraction efficiency of 10% or less.
(Item 17)
The eyepiece waveguide according to item 1, wherein the diffraction efficiency of the diffraction feature in the MPE region varies spatially.
(Item 18)
The eyepiece waveguide according to item 1, wherein the ICG region includes a one-dimensional periodic lattice.
(Item 19)
The eyepiece waveguide according to item 1, wherein the one-dimensional periodic lattice in the ICG region is a blazed lattice.
(Item 20)
The eyepiece waveguide according to item 1, wherein the EPE region includes a one-dimensional periodic lattice.
(Item 21)
The eyepiece waveguide according to item 20, wherein the one-dimensional periodic lattice in the EPE region includes a plurality of lines curved so as to apply a refractive power to the output beam.
(Item 22)
The eyepiece waveguide according to item 1, wherein the input beam is collimated and has a diameter of 5 mm or less.
(Item 23)
The eyepiece waveguide according to item 1, wherein the MPE region and the EPE region do not overlap.
(Item 24)
The eyepiece waveguide according to item 1, wherein the optically transmissive substrate is a flat surface.
(Item 25)
The eyepiece waveguide according to item 1, wherein the eyepiece waveguide is incorporated in an eyepiece for an augmented reality display system.
(Item 26)
The eyepiece waveguide according to item 25, wherein the eyepiece is configured to display a color image on a plurality of depth planes.
(Item 27)
The ICG region is configured to receive a set of input beams of a plurality of lights and combine the set of input beams into the substrate as a set of guided beams, the set of guided beams being at least partially. , The k-space ring is associated with a set of k-vectors in k-space within the k-space ring associated with the eyepiece lens waveguide, and the k-space ring is associated with guided propagation within the eyepiece lens waveguide. Corresponds to the area in the k-space that has been created,
The MPE region is configured to diffract a set of guided beams so as to create at least three sets of diffracted beams, the set of diffracted beams being at least partially within the k-space ring. Associated with at least three sets of k-vectors at three different angular locations,
The eyepiece waveguide according to item 1.
(Item 28)
28. The eyepiece waveguide according to item 27, wherein the set of k-vectors associated with the set of guided beams is entirely within the k-space ring.
(Item 29)
28. The eyepiece waveguide according to item 27, wherein the set of k-vectors associated with the set of diffracted beams is entirely within the k-space ring.
(Item 30)
27. The eyepiece waveguide according to item 27, wherein the set of k-vectors associated with the set of diffracted beams is angularly spaced from each other within the k-space ring by at least 45 degrees.
(Item 31)
27. The eyepiece waveguide according to item 27, wherein the k-vector sets associated with the individual sets of diffracted beams do not overlap with each other.
(Item 32)
One of the k-vector sets associated with the diffracted beam set is located at an angular position in the k-space ring corresponding to the direction from the ICG region to the MPE region. 27. The eyepiece waveguide.
(Item 33)
One of the k-vector sets associated with the diffracted beam set is located at an angular position in the k-space ring corresponding to the direction from the MPE region to the EPE region. 27. The eyepiece waveguide.
(Item 34)
The MPE region is configured to diffract a set of guided beams so as to create at least four sets of diffracted beams, the set of diffracted beams being at least partially within the k-space ring. 27. The eyepiece waveguide of item 27, associated with at least four sets of k-vectors at four different angular positions.
(Item 35)
While the diffracted beam propagates within the MPE region, the MPE region so that its corresponding set of k-vectors transitions between three different locations within the k-space ring. The eyepiece waveguide according to item 27, which is configured to be further diffracted.
(Item 36)
The eyepiece waveguide according to item 27, wherein the set of input beams is associated with an input image.
(Item 37)
The eyepiece waveguide according to item 1, wherein the input beam corresponds to the center of the input image and is vertically incident on the ICG region.
(Item 38)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupled lattice (ICG) region formed on or within the substrate, the ICG region receiving a set of input beams of light and introducing the set of input beams into the substrate. Configured to combine as a set, the set of guided beams is at least partially associated with a set of k-vectors in k-space within the k-space ring associated with the eyepiece waveguide. The k-space ring corresponds to the ICG region, which corresponds to the region in the k-space associated with the guided propagation in the eyepiece waveguide.
A multidirectional pupil expander (MPE) region formed on or within the substrate, the MPE region being positioned to receive the set of guided beams from the ICG region, at least three sets. The set of diffracted beams is configured to diffract the set of guided beams so as to create a diffracted beam of, and the set of diffracted beams is associated with at least three sets of k-vectors, the at least three sets of k-vectors. With an MPE region, which is at least partially within the k-space ring and is centered at three different angular locations.
An exit pupil expander (EPE) region formed on or within the substrate, the EPE region receiving one of the set of diffracted beams from the MPE region and receiving them optically. With the EPE region, which is positioned to externally couple as an output beam from a transmissive substrate.
Equipped with an eyepiece waveguide.
(Item 39)
38. The eyepiece waveguide according to item 38, wherein the set of k-vectors associated with the set of guided beams is entirely within the k-space ring.
(Item 40)
38. The eyepiece waveguide according to item 38, wherein the set of k-vectors associated with the set of diffracted beams is entirely within the k-space ring.
(Item 41)
38. The eyepiece waveguide according to item 38, wherein the set of k-vectors associated with the set of diffracted beams is angularly spaced from each other within the k-space ring by at least 45 degrees.
(Item 42)
38. The eyepiece waveguide according to item 38, wherein the k-vector sets associated with the individual sets of diffracted beams do not overlap with each other.
(Item 43)
One of the k-vector sets associated with the diffracted beam set is located at an angular position in the k-space ring corresponding to the direction from the ICG region to the MPE region. 38. The eyepiece waveguide.
(Item 44)
One of the k-vector sets associated with the diffracted beam set is located at an angular position in the k-space ring corresponding to the direction from the MPE region to the EPE region. 38. The eyepiece waveguide.
(Item 45)
The MPE region is configured to diffract a set of guided beams so as to create at least four sets of diffracted beams, the set of diffracted beams being at least partially within the k-space ring. 38. The eyepiece waveguide according to item 38, which is associated with at least four sets of k-vectors centered at four different angular positions.
(Item 46)
While the diffracted beam propagates within the MPE region, the MPE region is such that its corresponding set of k-vectors transitions between three different locations within the k-space ring. 38. The eyepiece waveguide configured to further diffract.
(Item 47)
38. The eyepiece waveguide associated with the input image.
(Item 48)
38. The eyepiece waveguide according to item 38, wherein the MPE region comprises a plurality of diffraction features exhibiting periodicity along at least a first periodic axis and a second periodic axis.
(Item 49)
38. The eyepiece waveguide according to item 38, wherein the MPE region comprises a two-dimensional lattice pattern with distinct diffraction features.
(Item 50)
38. The eyepiece waveguide according to item 38, wherein the MPE region comprises a cross grid.
(Item 51)
38. The eyepiece waveguide according to item 38, wherein each of the input beams is collimated and has a diameter of 5 mm or less.
(Item 52)
The eyepiece waveguide according to item 37, wherein the MPE region and the EPE region do not overlap.
(Item 53)
The eyepiece waveguide according to item 38, wherein the eyepiece waveguide is incorporated into an eyepiece for an augmented reality display system.
(Item 54)
The eyepiece waveguide according to item 53, wherein the eyepiece is configured to display a color image on a plurality of depth planes.
(Item 55)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
An input coupling region for receiving an input beam of light associated with an image, wherein the input beam of light has an input coupling region having an associated pupil.
A multidirectional pupil expander (MPE) region configured to expand the pupil in at least three directions.
With an emission region for projecting the output beam of light associated with the image
Equipped with an eyepiece waveguide.
(Item 56)
55. The eyepiece waveguide according to item 55, wherein the MPE region is configured to expand the pupil size in at least four directions.
(Item 57)
The eyepiece waveguide according to item 55, wherein the MPE region and the emission region do not overlap.
(Item 58)
The eyepiece waveguide according to item 55, wherein the MPE region creates an aperiodic array of output pupils.
(Item 59)
38. The eyepiece waveguide of item 38, wherein the central beam of the set of input beams is vertically incident on the ICG region.
(Item 60)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling grid (ICG) region formed on or within the substrate, wherein the ICG region is:
Receiving a set of input beams of light, said set of input beams is associated with a set of k-vectors in k-space.
By diffracting the set of input beams so as to create a set of first guided beams and a set of first non-diffracted beams, the first set of guided beams is the eyepiece waveguide. Corresponding to the parallel movement subset of the k-vector within the k-space ring associated with the tube, the first set of non-diffraction beams is the parallel movement of the k-vector outside the k-space ring. Corresponding to a subset, the k-space ring corresponds to a region in k-space associated with guided propagation within the eyepiece lens waveguide.
By diffracting the set of input beams so as to create a separate set of second guided beams and a separate set of second non-diffracted beams, the second set of guided beams is said to be said. Corresponding to the translational subset of the k-vector within the k-space ring, the second set of non-diffraction beams corresponds to the translational subset of the k-vector outside the k-space ring. And that
The ICG area, which is configured to do
A first pupil expander region formed on or within the substrate, wherein the first pupil expander region is positioned to receive the first set of guided beams from the ICG region. , A first pupil expander region configured to replicate them as a set of first replica beams,
A second pupil expander region formed on or within the substrate, wherein the second pupil expander region is positioned to receive the set of the second guided beam from the ICG region. , A second pupil expander region configured to replicate them as a set of second replica beams,
An exit region formed on or within the substrate, wherein the exit region is positioned to receive a set of the first and second replicated beams, which the exit region uses as an output beam. Configured to be externally coupled, the output beam represents an exit region that represents the complete set of input beams.
Equipped with an eyepiece waveguide.
(Item 61)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling grid (ICG) region formed on or within the substrate, wherein the ICG region is:
Receiving a set of input beams of light, said set of input beams is associated with a set of k-vectors forming a field of view (FOV) shape in k-space, the FOV shape being said eyepiece. The k-space ring has a first dimension in k-space that is greater than the width of the k-space ring associated with the waveguide, and the k-space ring is associated with guided propagation within the eyepiece lens waveguide. Corresponding to the area in space,
The input beam is moved so that the input beam is coupled into the substrate as a guided beam and the FOV shape is translated into both the first and second positions in the k-space ring. By diffracting, at the first position, part of the FOV shape is outside the k-space ring and only the first subpart of the FOV shape is inside the k-space ring. Yes, at the second position, part of the FOV shape is outside the k-space ring and only the second subpart of the FOV shape is inside the k-space ring.
The ICG area, which is configured to do
A plurality of pupil expander regions formed on or within the substrate, wherein the plurality of pupil expander regions have the first and second subparts of the FOV shape, and the complete FOV shape. With a plurality of pupil expander regions positioned to diffract the guided beam so as to translate into a third position within the k-space ring to be reassembled.
Equipped with an eyepiece waveguide.
(Item 62)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupled lattice (ICG) region formed on or within the substrate, the ICG region receiving a set of input beams of light and introducing the set of input beams into the substrate. Configured to combine as a set, the set of input beams is associated with a set of k-vectors in k-space, and the set of k-vectors is associated with the eyepiece lens waveguide. An ICG having a first dimension in k-space that is greater than the width of the space ring, wherein the k-space ring corresponds to a region in k-space associated with guided propagation within the eyepiece lens waveguide. Area and
A plurality of pupil expander regions formed on or within the substrate, wherein the plurality of pupil expander regions collectively receive the guided beam from the ICG region and create a set of duplicate beams. With multiple pupil expander regions, positioned to diffract them,
An exit region formed on or within the substrate that receives the replica beam and delivers the replica beam from the optically transmissive substrate to a complete set of input beams. With the exit region, which is positioned to be externally coupled as a set of output beams to represent
Equipped with an eyepiece waveguide.
(Item 63)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling grating (ICG) region formed on or within the substrate, the ICG region being configured to diffract a set of input beams of light corresponding to an input image to a plurality of diffraction orders. The diffraction grating is provided, and the diffraction grating is

It has a period Λ that satisfies, n ₂ is the refractive index of the optically transmissive substrate, n ₁ is the refractive index of the medium surrounding the optically transmissive substrate, and ω is. , The angular frequency of the light input beam, where c is the constant of the speed of light, the ICG region, and
A plurality of pupil expander regions formed on or within the substrate, wherein the plurality of pupil expander regions collectively receive the beam from the ICG region and create a set of duplicate beams. With multiple pupil expander regions, positioned to diffract them,
An exit region formed on or within the substrate that receives the duplicate beam and outputs the duplicate beam from the optically transmissive substrate to represent the complete input image. With the emission region, which is positioned to be externally coupled as a set of beams
Equipped with an eyepiece waveguide.
(Item 64)
An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
An optically transparent substrate having a first surface and a second surface,
A first input coupling grid (ICG) region formed on one of the surfaces of the substrate or within one of the surfaces of the substrate, wherein the first ICG region is the input of light. A first ICG region configured to receive the beam and couple the input beam into the substrate as a guided beam.
A multidirectional pupil expander (MPE) region formed on a first surface of the substrate or within the first surface of the substrate, wherein the MPE region is at least a first periodic axis and a second. The MPE region receives the guided beam from the first ICG region and diffracts it in a plurality of directions to generate a plurality of diffracted beams. The MPE area, which is positioned to be created,
An exit pupil expander (EPE) region formed on a second surface of the substrate or within the second surface of the substrate, wherein the EPE region overlaps the MPE region, and the EPE region is a region. With an EPE region configured to externally couple one or more of the diffracted beams from the optically transmissive substrate as an output beam.
Equipped with an eyepiece waveguide.

FIG. 1 illustrates a user's view of an augmented reality (AR) scene through an AR device.

FIG. 2 illustrates an embodiment of a wearable display system.

FIG. 3 illustrates a conventional display system for simulating a 3D image for a user.

FIG. 4 illustrates aspects of an approach for simulating a 3D image using multiple depth planes.

5A-5C illustrate the relationship between the radius of curvature and the radius of focal point.

FIG. 6 illustrates an example of a waveguide stack for outputting image information to a user in an AR eyepiece.

7A-7B illustrate an example of an emitted beam output by a waveguide.

FIG. 8 illustrates an embodiment of a stacked waveguide assembly, where each depth plane contains an image formed using a plurality of different primary colors.

FIG. 9A illustrates cross-sectional side views of an embodiment of a set of stacked waveguides, each including an internally coupled optical element.

FIG. 9B illustrates a perspective view of an embodiment of the plurality of stacked waveguides of FIG. 9A.

FIG. 9C illustrates a top-down plan view of an embodiment of the plurality of stacked waveguides of FIGS. 9A and 9B.

FIG. 10 is a perspective view of an exemplary AR eyepiece waveguide stack.

FIG. 11 is a cross-sectional view of a portion of an exemplary eyepiece waveguide stack with an edge seal structure for supporting the eyepiece waveguide in a stacked configuration.

12A and 12B illustrate top views of the eyepiece waveguide during operation when projecting an image towards the user's eye. 12A and 12B illustrate top views of the eyepiece waveguide during operation when projecting an image towards the user's eye.

FIG. 13A illustrates a k-vector that can be used to represent the propagation direction of a ray or light beam.

FIG. 13B illustrates light rays in a planar waveguide.

FIG. 13C illustrates an acceptable k-vector for light at a given angular frequency ω propagating in a non-boundary homogeneous medium with a refractive index n.

FIG. 13D illustrates an acceptable k-vector for light at a given angular frequency ω propagating in a homogeneous planar waveguide medium with a refractive index n.

FIG. 13E illustrates a ring in k-space corresponding to a k-vector of light waves that can be induced in a waveguide having a refractive index n ₂ .

FIG. 13F illustrates the relationship between the k-vector and the density of interactions between the guided beam corresponding to the k-vector and the diffraction grating formed on or in the waveguide, in the k-space. A schematic and an eyepiece waveguide are shown.

FIG. 13G illustrates a top view of the grating and some of its associated k-space grating vectors (G-2, G-1, G1, G2).

FIG. 13H illustrates the side view of the diffraction grating and its effect in k-space over the k-vector corresponding to the normal incident ray or beam of light.

FIG. 13I illustrates the side view of the diffraction grating shown in FIG. 13G and its effect in k-space over the k-vector corresponding to the obliquely incident light or beam of light.

FIG. 13J is a k-space schematic diagram illustrating the field of view of an image projected into an AR eyepiece waveguide.

FIG. 13K is a k-space schematic showing the translational shift in the k-space of the FOV rectangle caused by the input coupling lattice (ICG) located at the entrance pupil of the eyepiece waveguide.

FIG. 14A illustrates an exemplary eyepiece waveguide with an ICG region, an orthogonal pupil expander (OPE) region, and an exit pupil expander (EPE) region.

FIG. 14B illustrates the k-space effect of the eyepiece waveguide shown in FIG. 14A.

FIG. 14C illustrates the optical activity of the OPE region shown in FIGS. 14A and 14B.

FIG. 14D illustrates techniques for determining the size and shape of the OPE and EPE regions.

FIG. 15A illustrates an exemplary embodiment of a waveguide eyepiece in which the OPE region is tilted so that its lower border is parallel to the upper border of the EPE region.

FIG. 15B includes a k-space schematic illustrating the action of the eyepiece waveguide shown in FIG. 15A.

FIG. 15C is another k-space schematic illustrating the action of the eyepiece waveguide shown in FIG. 15A.

FIG. 15D is a schematic representation of the first generation of interaction between the input beam and the OPE region of the eyepiece waveguide embodiment shown in FIG. 15A.

FIG. 15E is a schematic representation of the second generation of interaction between the input beam and the OPE region of the eyepiece waveguide embodiment shown in FIG. 15A.

FIG. 15F is a schematic representation of the third generation of interaction between the input beam and the OPE region of the eyepiece waveguide embodiment shown in FIG. 15A.

FIG. 15G is a schematic diagram illustrating how a single input beam from the ICG region is replicated by the OPE region and redirected as multiple beams towards the EPE region.

FIG. 16A illustrates an exemplary eyepiece waveguide having a multidirectional pupil expander (MPE) region rather than an OPE region.

FIG. 16B illustrates a portion of an exemplary 2D lattice that can be used within the MPE region shown in FIG. 16A, along with its associated lattice vector.

FIG. 16C is a schematic k-space diagram illustrating the k-space effect of the MPE region of the eyepiece waveguide shown in FIG. 16A.

FIG. 16D is a schematic k-space diagram further illustrating the k-space effect of the MPE region of the eyepiece waveguide shown in FIG. 16A.

FIG. 16E is a schematic k-space diagram illustrating the k-space action of the eyepiece waveguide shown in FIG. 16A.

FIG. 16F is a schematic representation of the first generation of interaction between the input beam and the MPE region of the eyepiece waveguide embodiment shown in FIG. 16A.

FIG. 16G is a schematic representation of the second generation of interaction between the input beam and the MPE region of the eyepiece waveguide embodiment shown in FIG. 16A.

FIG. 16H is a schematic representation of the third generation of interaction between the input beam and the MPE region of the eyepiece waveguide embodiment shown in FIG. 16A.

FIG. 16I is a schematic representation of the fourth generation of interaction between the input beam and the MPE region of the eyepiece waveguide embodiment shown in FIG. 16A.

FIG. 16J is a schematic diagram illustrating various paths through which the beam can follow through the MPE region and finally to the EPE region according to the eyepiece waveguide embodiment shown in FIG. 16A.

FIG. 16K is a schematic diagram illustrating how a single input beam from the ICG region is replicated by the MPE region and redirected as multiple beams towards the EPE region.

FIG. 16L is a control comparison illustrating the performance of an eyepiece waveguide with an OPE region vs. an eyepiece waveguide with an MPE region.

FIG. 16M further illustrates the performance of the eyepiece waveguide with the MPE region vs. the eyepiece waveguide with the OPE region.

FIG. 17A illustrates a portion of an exemplary 2D lattice that can be used within the MPE region of an eyepiece waveguide, along with its associated lattice vector.

FIG. 17B is a schematic k-space diagram illustrating the k-space action of the MPE region of the eyepiece waveguide.

FIG. 17C is a schematic k-space diagram illustrating the k-space effect of an eyepiece waveguide with an MPE region.

FIG. 17D is a schematic representation of the first generation of interaction between the input beam and the MPE region of the eyepiece waveguide.

FIG. 17E is a schematic representation of the second generation of interaction between the input beam and the MPE region of the eyepiece waveguide.

FIG. 17F is a schematic representation of the third generation of interaction between the input beam and the MPE region of the eyepiece waveguide.

FIG. 17G is a schematic representation of the fourth generation of interaction between the input beam and the MPE region of the eyepiece waveguide.

FIG. 18A illustrates an exemplary eyepiece waveguide with an ICG region, two orthogonal pupil expander regions, and an exit pupil expander region.

18B and 18C illustrate the top view of the EPE region of the eyepiece waveguide shown in FIG. 18A. 18B and 18C illustrate the top view of the EPE region of the eyepiece waveguide shown in FIG. 18A.

FIG. 19 illustrates an embodiment of an eyepiece waveguide with an extended field of view.

FIG. 20A illustrates an embodiment of an extended FOV eyepiece waveguide with an MPE region overlapped by an EPE region.

FIG. 20B illustrates a portion of an exemplary 2D lattice that can be used within the MPE region of the eyepiece waveguide in FIG. 20A, along with its associated lattice vector.

FIG. 20C is a schematic k-space diagram illustrating the k-space action of the ICG region of the eyepiece waveguide in FIG. 20A.

FIG. 20D is a schematic k-space diagram illustrating a portion of the k-space effect of the MPE region of the eyepiece waveguide in FIG. 20A.

FIG. 20E is a schematic k-space diagram illustrating another portion of the k-space effect of the MPE region of the eyepiece waveguide in FIG. 20A.

FIG. 20F is a k-space of the MPE region on the FOV rectangle from FIG. 20D, similar to FIG. 20E, but translated to the 9 o'clock position (instead of the 3 o'clock position as illustrated in FIG. 20E). Shows action.

FIG. 20G is a schematic k-space diagram illustrating the k-space effect of the EPE region in the eyepiece waveguide in FIG. 20A.

FIG. 20H is a schematic k-space diagram summarizing the k-space action of the eyepiece waveguide in FIG. 20A.

FIG. 20I is a schematic diagram illustrating how a beam of light diffuses through the eyepiece waveguide shown in FIG. 20A.

FIG. 20J illustrates a method by which the diffraction efficiency of the MPE region in the eyepiece waveguide in FIG. 20A can be spatially varied so as to improve the uniformity of luminance in the waveguide.

FIG. 20K illustrates how the diffraction efficiency of the EPE region in the eyepiece waveguide in FIG. 20A can be spatially varied so as to improve the uniformity of luminance in the waveguide.

FIG. 20L illustrates an embodiment of an eyepiece waveguide in FIG. 20A, comprising one or more diffraction mirrors around the peripheral edge of the waveguide.

FIG. 20M illustrates an exemplary embodiment of an eyeglass that incorporates one or more instances of the eyepiece waveguide in FIG. 20A.

FIG. 20N illustrates another exemplary embodiment of the spectacle that incorporates one or more instances of the eyepiece waveguide in FIG. 20A.

FIG. 21A illustrates another embodiment of an eyepiece waveguide with an MPE region overlapped by the EPE region.

FIG. 21B is a k-space schematic illustrating the k-space effect of the eyepiece waveguide in FIG. 20A on a set of first input beams corresponding to the first subpart of the FOV of the input image.

FIG. 21C is a k-space schematic illustrating the k-space effect of the eyepiece waveguide in FIG. 21A on a set of second input beams corresponding to a second sub-part of the FOV of the input image.

21D is a schematic k-space diagram summarizing the k-space action of the eyepiece waveguide in FIG. 21A.

FIG. 21E illustrates an exemplary embodiment of an eyeglass that incorporates one or more instances of the eyepiece waveguide in FIG. 21A.

FIG. 21F illustrates an exemplary FOV corresponding to the spectacles in FIG. 21E.

FIG. 21G illustrates the k-space effect of another embodiment of the eyepiece waveguide shown in FIG. 21A.

FIG. 22A illustrates an embodiment of an eyepiece waveguide capable of projecting an FOV extended in two directions.

22B illustrates the opposite side of the eyepiece waveguide shown in FIG. 22A.

FIG. 22C illustrates the k-space action of the ICG and OPE regions within the eyepiece waveguide embodiment in FIG. 22A.

FIG. 22D illustrates the k-space effect of the MPE region within the eyepiece waveguide embodiment in FIG. 22A.

FIG. 22E illustrates the k-space effect of the EPE region within the eyepiece waveguide embodiment in FIG. 22A.

FIG. 23 illustrates an exemplary embodiment of an eyepiece waveguide designed to work with an angled projector.

(Overview)
The present disclosure describes various eyepiece waveguides that can be used within an AR display system to project an image onto the user's eye. Eyepiece waveguides are described in both physical terms and the use of k-space representations.

(Exemplary HMD device)
FIG. 2 illustrates an embodiment of a wearable display system 60. The display system 60 includes a display or eyepiece 70 and various mechanical and electronic modules and systems to support the functionality of the display 70. The display 70 may be coupled to the frame 80, which is wearable by the display system user 90 and is configured to position the display 70 in front of the user 90's eyes. The display 70 may be considered eyewear in some embodiments. In some embodiments, the speaker 100 is coupled to the frame 80 and positioned adjacent to the ear canal of the user 90. The display system may also include one or more microphones 110 to detect sound. The microphone 110 can allow the user to provide an input or command to the system 60 (eg, voice menu command selection, natural language question, etc.) and / or another person (eg, a similar display). It can enable audio communication with other users of the system). The microphone 110 can also collect audio data (eg, sound from the user and / or the environment) from around the user. In some embodiments, the display system may also include a peripheral sensor 120a, which is separate from the frame 80 and attached to the body of the user 90 (eg, on the head, torso, limbs, etc.). You may. Peripheral sensors 120a may, in some embodiments, acquire data characterizing the physiological state of user 90.

The display 70 is operably coupled to the local data processing module 140 by a communication link 130 such as a wired lead or wireless connectivity, which is secured to a user-worn helmet or hat that is secured and attached to the frame 80. It can be mounted in a variety of configurations, such as being mounted in the headphone, built into the headphones, or removably mounted by the user 90 (eg, in a backpack configuration or in a belt-coupled configuration). Similarly, the sensor 120a may be operably coupled to the local processor and data module 140 by a communication link 120b (eg, wired conductor or wireless connectivity). Local processing and data modules 140 may include digital memory such as hardware processors and non-volatile memory (eg, flash memory or hard disk drives), both to assist in processing, caching, and storing data. Can be used. Data include 1) image capture devices (eg, cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, wireless devices, gyroscopes, and / or other sensors disclosed herein (eg,). For example, data captured from a sensor (which may be operably coupled to frame 80 or otherwise attached to user 90) and / or 2) possibly for passage to display 70 after processing or reading. May include data acquired and / or processed using the remote processing module 150 and / or the remote data repository 160 (including data related to virtual content). The local processing and data module 140 is such that these remote modules 150, 160 are operably coupled to each other and are available as resources for the local processing and data module 140, via a wired or wireless communication link or the like. Communication links 170, 180 may be operably coupled to the remote processing module 150 and the remote data repository 160. In some embodiments, the local processing and data module 140 comprises one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a wireless device, and / or a gyroscope. It may be included. In some other embodiments, one or more of these sensors may be attached to the frame 80 or an independent device that communicates with the local processing and data module 140 via a wired or wireless communication path. May be.

The remote processing module 150 may include one or more processors for analyzing and processing data such as images and audio information. In some embodiments, the remote data repository 160 may be a digital data storage facility, which may be available through the Internet or other networking configurations in a "cloud" resource configuration. In some embodiments, the remote data repository 160 provides information (eg, information for generating augmented reality content) to the local and / or remote processing modules 140 and / or one or more remotes. It may include a server. In other embodiments, all data is stored and all calculations are performed in local processing and data modules, allowing for fully autonomous use from remote modules.

Perception of an image as "three-dimensional" or "3-D" can be achieved by providing a slightly different presentation of the image to each eye of the user. FIG. 3 illustrates a conventional display system for simulating 3D image data about a user. Two distinctly different images 190, 200, one for each eye 210, 220, are output to the user. The images 190, 200 are separated from the eyes 210, 220 by a distance 230 along an optical axis parallel to the user's line of sight or a z-axis. Images 190, 200 are flat, and eyes 210, 220 can be focused on the image by taking a single perspective-adjusted state. Such a 3-D display system relies on the human visual system to combine images 190, 200 to provide perception of the depth and / or scale of the combined images.

However, the human visual system is complex and it is difficult to provide a realistic perception of depth. For example, many users of conventional "3-D" display systems may find such systems uncomfortable or may not perceive a sense of depth at all. Objects can be perceived as "three-dimensional" due to the combination of convergence and accommodation. The movement of the convergence and divergence movements of the two eyes relative to each other (eg, the pupils move toward or away from each other, converging the individual gazes of the eyes and staring at the object. Rotation) is closely associated with focusing (or "accommodation") of the crystalline lens of the eye. Under normal conditions, the change in focus of the lens of the eye or the accommodation of the eye to change the focus from one object to another at different distances is "accommodation-accommodation / divergent motion reflex" and mydriasis or Under the relationship known as miosis, it will automatically cause a consistent change in converging / divergent motion at the same distance. Similarly, under normal conditions, changes in convergence and divergence will induce matching changes in lens shape and accommodation of pupil size. As described herein, many stereoscopic or "3-D" display systems present slightly different (and therefore slightly different) presentations to each eye so that the 3D viewpoint is perceived by the human visual system. Image) is used to display the scene. However, such systems are uncomfortable for many users because they simply provide the image information in a single perspective-adjusted state and work against the "accommodation-convergence / divergent motion reflex". possible. A display system that provides better accommodation between accommodation and convergence / divergence motion can form a more realistic and comfortable simulation of 3D image data.

FIG. 4 illustrates aspects of an approach for simulating 3D image data using multiple depth planes. Referring to FIG. 4, the eyes 210, 220 take different perspective-adjusted states and focus the object at various distances on the z-axis. As a result, a particular perspective-adjusted state is associated so that an object or part of an object in a particular depth plane is in focus when the eye is in the perspective-adjusted state with respect to that depth plane. It can be said that it is associated with a specific one of the illustrated depth planes 240 having a focal length. In some embodiments, the 3D image data is simulated by providing different presentations of the image for each eye 210, 220, and by providing different presentations of the image corresponding to different depth planes. You may. The individual visual fields of the eyes 210, 220 are shown to be separate for clarity of illustration, but they may overlap, for example, as the distance along the z-axis increases. In addition, for ease of illustration, the depth plane is shown to be flat, but the contours of the depth plane are in focus with the eye in a particular perspective-adjusted state with all features in the depth plane. It should be understood that it can be curved in physical space as it does.

The distance between an object and the eye 210 or 220 can also vary the amount of light emitted from the object as perceived by the eye. 5A-5C illustrate the relationship between distance and ray divergence. The distance between the object and the eye 210 is represented in the order of reduced distances R1, R2, and R3. As shown in FIGS. 5A-5C, the rays diverge more as the distance to the object decreases. As the distance increases, the rays are more collimated. In other words, a light field generated by a point (an object or part of an object) can be said to have a spherical wavefront curvature, which is a function of the distance the point is away from the user's eye. The curvature increases as the distance between the object and the eye 210 decreases. As a result, in different depth planes, the divergence of the rays is also different, and the divergence increases as the distance between the depth plane and the user's eye 210 decreases. Although only monocular 210 is illustrated in FIGS. 5A-5C and other figures herein for clarity of illustration, the discussion of eye 210 may apply to the user's binoculars 210 and 220. I want you to understand.

A highly authentic simulation of the perceived depth can be achieved by providing the eye with different presentations of images corresponding to each of a limited number of depth planes. The different presentations are focused separately by the user's eye, thereby based on the amount of accommodation required to focus on different image features for scenes located on different depth planes, and. / Or may help provide a depth signal to the user based on the observation of different image features on different out-of-focus depth planes.

(Examples of Waveguide Stack Assembly for AR or MR Eyepieces)
FIG. 6 illustrates an example of a waveguide stack for outputting image information to a user in an AR eyepiece. The display system 250 may utilize multiple waveguides 270, 280, 290, 300, 310 to provide three-dimensional perception to the eye / brain, a stack of waveguides or a stacked guide. Includes waveguide assembly 260. In some embodiments, the display system 250 is the system 60 of FIG. 2, where FIG. 6 graphically illustrates some parts of the system 60 in more detail. For example, the waveguide assembly 260 may be part of the display 70 of FIG. It should be appreciated that the display system 250 may be considered as a light field display in some embodiments.

The waveguide assembly 260 may also include a plurality of features 320, 330, 340, 350 between the waveguides. In some embodiments, features 320, 330, 340, 350 may be one or more lenses. Waveguides 270, 280, 290, 300, 310 and / or multiple lenses 320, 330, 340, 350 are configured to transmit image information to the eye with varying levels of wavefront curvature or ray divergence. You may. Each waveguide level may be associated with a particular depth plane and may be configured to output image information corresponding to that depth plane. The image input device 360, 370, 380, 390, 400 may function as a light source for the waveguide, in order to input image information into the waveguide 270, 280, 290, 300, 310. Each may be utilized and may be configured to disperse incident light across each individual waveguide for output towards the eye 210, as described herein. Light is emitted from the output surfaces 410, 420, 430, 440, 450 of each individual image input device 360, 370, 380, 390, 400 and corresponds to the individual waveguides 270, 280, 290, 300, 310. The input surface is 460, 470, 480, 490, 500. In some embodiments, the input surfaces 460, 470, 480, 490, 500 may be the edges of the corresponding waveguides, respectively.
Alternatively, it may be part of the corresponding main surface of the waveguide (ie, one of the world 510 or one of the waveguide surfaces directly facing the user's eye 210). In some embodiments, a beam of light (eg, a collimated beam) may be injected into each waveguide and is replicated by refraction in the waveguide, such as by sampling to a beamlet. Then, it may be directed towards the eye 210 with the amount of refractive power corresponding to the depth plane associated with that particular waveguide. In some embodiments, one of the image input devices 360, 370, 380, 390, 400 is a plurality of (eg, three) waveguides 270, 280, 290, 300, 310. It may be associated and light may be cast into it.

In some embodiments, the image input devices 360, 370, 380, 390, 400 generate image information for input into the corresponding waveguides 270, 280, 290, 300, 310, respectively. , Discrete display. In some other embodiments, the image input device 360, 370, 380, 390, 400 transfers image information via one or more optical conduits (such as fiber optic cables) to the image input device 360, 370, 380, It is the output end of a single multiplexed display that can be transmitted to each of the 390 and 400. It should be understood that the image information provided by the image input devices 360, 370, 380, 390, 400 may include light of different wavelengths or colors.

In some embodiments, the light emitted into the waveguides 270, 280, 290, 300, 310 is provided by an optical projector system 520, which includes an optical module 530, which is a light emitting diode. It may include a light source such as (LED) or a light emitter. The light from the optical module 530 may be directed and modulated by an optical modulator 540 (eg, a spatial light modulator) via a beam splitter (BS) 550. The light modulator 540 may vary the perceived intensity of light emitted into the waveguides 270, 280, 290, 300, 310 spatially and / or temporally. Examples of spatial light modulators include liquid crystal displays (LCDs) and digital light processing (DLP) displays, including liquid crystal on silicon (LCOS) displays.

In some embodiments, the optical projector system 520 or one or more components thereof may be attached to the frame 80 (FIG. 2). For example, the optical projector system 520 may be part of the vine portion of the frame 80 (eg, the ear hook 82) or may be located on the edge of the display 70. In some embodiments, the optical module 530 may be separate from the BS 550 and / or the light modulator 540.

In some embodiments, the display system 250 places light in one or more waveguides 270, 280, 290, 300, 310 in various patterns (eg, raster scans, spiral scans, lisaju patterns, etc.). Finally, it may be a scanning fiber display comprising one or more scanning fibers for projection into the user's eye 210. In some embodiments, the illustrated image input devices 360, 370, 380, 390, 400 are such that light is emitted into one or more waveguides 270, 280, 290, 300, 310. A single scanning fiber or a bundle of scanning fibers configured may be graphically represented. In some other embodiments, the illustrated image input device 360, 370, 380, 390, 400 may graphically represent a plurality of scan fibers or bundles of scan fibers, each waveguide light. It is configured to be charged into one of the associated tubes 270, 280, 290, 300, 310. One or more optical fibers may transmit light from the optical module 530 to one or more waveguides 270, 280, 290, 300, and 310. In addition, one or more intervening optics are provided between the scanning fiber or the plurality of fibers and the one or more waveguides 270, 280, 290, 300, 310 and exit, for example, from the scanning fiber. Light may be redirected into one or more waveguides 270, 280, 290, 300, 310.

The controller 560 controls the operation of the stacked waveguide assembly 260, including the operation of the image input devices 360, 370, 380, 390, 400, light source 530, and optical module 540. In some embodiments, the controller 560 is part of the local data processing module 140. Controller 560 includes programming (eg, instructions in a non-transient medium) that coordinates the timing and provision of image information to waveguides 270, 280, 290, 300, 310. In some embodiments, the controller may be a single integrated device or a distributed system connected by a wired or wireless communication channel. The controller 560 may, in some embodiments, be part of the processing module 140 or 150 (FIG. 2).

The waveguides 270, 280, 290, 300, 310 may be configured to propagate light within each individual waveguide by total internal reflection (TIR). Waveguides 270, 280, 290, 300, 310 are planar or separate, with edges extending between the main top and bottom surfaces and their main top and bottom surfaces, respectively. It may have a shape (eg, curvature). In the illustrated configuration, the waveguides 270, 280, 290, 300, and 310 each redirect light, propagate it within each individual waveguide, and output image information from the waveguide to the eye 210. May include externally coupled optical elements 570, 580, 590, 600, 610 configured to extract light from the waveguide. The extracted light can also be referred to as externally coupled light, and the optical element that externally couples the light can also be referred to as an optical extraction optical element. The beam of light extracted can be output by the waveguide where the light propagating within the waveguide hits the optical extraction optical element. Externally coupled optical elements 570, 580, 590, 600, 610 may be diffractive optical features, including, for example, diffraction gratings as further discussed herein. Externally coupled optical elements 570, 580, 590, 600, 610 are arranged and illustrated on the bottom main surface of the waveguides 270, 280, 290, 300, 310, but in some embodiments they are. As further discussed herein, they may be placed on the top main surface and / or the bottom main surface, and / or placed directly within the volume of the waveguides 270, 280, 290, 300, 310. May be good. In some embodiments, the outer coupling optics 570, 580, 590, 600, 610 are mounted in a transparent substrate and formed in a layer of material forming the waveguides 270, 280, 290, 300, 310. May be done. In some other embodiments, the waveguides 270, 280, 290, 300, 310 may be monolithic material components, and the outer coupling optical elements 570, 580, 590, 600, 610 are material components thereof. It may be formed on and / or inside the surface of the.

Each waveguide 270, 280, 290, 300, 310 may output light to form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye may deliver a beam of collimated light to the eye 210. The collimated beam of light can represent an optical infinity plane. The next upper waveguide 280 may output a beam of collimated light that passes through a first lens 350 (eg, a negative lens) before reaching the eye 210. The first lens 350 is slightly convex so that the eye / brain interprets the light generated from its waveguide 280 as coming from a first focal plane that is closer inward toward the eye 210 from optical infinity. Wavefront curvature may be added to the collimated beam. Similarly, the third waveguide 290 passes its output light through both the first lens 350 and the second 340 lens before reaching the eye 210. The combined refractive power of the first lens 350 and the second 340 lens is more optical to the eye / brain than the light generated from the third waveguide 290 was from the second waveguide 280. Another increasing amount of wavefront curvature may be added so that it is interpreted as originating from a second focal plane that is closer to inward from infinity.

The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, with the highest waveguide 310 in the stack looking at its output due to the aggregate focal force representing the focal plane closest to the person. Sends through all of the lenses between and. When viewing / interpreting light emanating from the world 510 on the other side of the stacked waveguide assembly 260, a compensating lens layer 620 is placed at the top of the stack to compensate for the stack of lenses 320, 330, 340, 350. It may be arranged to compensate for the aggregated power of the lower lens stacks 320, 330, 340, 350. Such a configuration provides the same number of perceived focal planes as the available waveguide / lens pairs. Both the externally coupled optics of the waveguide and the focused side of the lens may be static (ie, not dynamic or electrically active). In some alternative embodiments, one or both may be dynamic using electrically active features.

In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 may output images set in the same depth plane, or multiple subsets of waveguides 270, 280, 290, 300, 310. However, you may output an image set in the same plurality of depth planes with one set for each depth plane. This may provide the advantage of forming tiled images to provide an expanded field of view in those depth planes.

Externally coupled optics 570, 580, 590, 600, 610 redirect light from their individual waveguides for a particular depth plane associated with the waveguide, and direct this light in the appropriate amount. It may be configured to output with divergence or colimation of. As a result, waveguides with different associated depth planes may have different configurations of externally coupled optical elements 570, 580, 590, 600, 610, depending on the associated depth plane. , Outputs light with different amounts of divergence. In some embodiments, the light extraction optics 570, 580, 590, 600, 610 may be volumetric or surface features, which may be configured to output light at a specific angle. good. For example, the optical extraction optical elements 570, 580, 590, 600, 610 may be volumetric holograms, surface holograms, and / or diffraction gratings. In some embodiments, features 320, 330, 340, 350 do not have to be lenses. Rather, they may simply be spacers (eg, structures for forming cladding layers and / or voids).

In some embodiments, the externally coupled optics 570, 580, 590, 600, 610 are redirected towards the eye 210 with each interaction only part of the power of light in the beam. The rest, on the other hand, are diffractive features with sufficiently low diffraction efficiency so that they continue to move through the waveguide via the TIR. Therefore, the exit pupil of the optical module 530 is replicated across the waveguide, creating multiple output beams that carry image information from the light source 530, where the eye 210 can capture the duplicated exit pupil. Effectively expand the number of. These diffraction features may also have variable diffraction efficiencies across their geometry and improve the uniformity of the light output by the waveguide.

In some embodiments, the one or more diffraction features may be switchable between an actively diffracting "on" state and a significantly non-diffractive "off" state. For example, the switchable diffraction element may include a layer of polymer dispersed liquid crystal, in which the microdroplets form a diffraction pattern in the host medium, the refractive index of the microdroplets being the refractive index of the host material. It may be switched to substantially match (in which case the pattern does not significantly diffract the incident light), or the microdroplets may be switched to a refractive index that does not match that of the host medium (in which case). In that case, the pattern actively diffracts the incident light).

In some embodiments, a camera assembly 630 (eg, a digital camera, including visible and IR light cameras) is provided with an eye 210, a portion of the eye 210, or at least a portion of the tissue surrounding the eye 210. The image of the camera may be captured, for example, the user input may be detected, biometric information may be extracted from the eye, the direction of the line of sight of the eye may be estimated and tracked, the physiological state of the user may be monitored, and the like. In some embodiments, the camera assembly 630 is an image capture device and a light source for projecting light (eg, IR or near IR light) onto the eye, which light is then reflected by the eye and captured. Can be detected by) and may be included. In some embodiments, the light source comprises a light emitting diode (“LED”) that emits an IR or near IR thereof. In some embodiments, the camera assembly 630 may be mounted on the frame 80 (FIG. 2) and may be telecommunications with the processing module 140 or 150, which processes the image information from the camera assembly 630. However, various decisions can be made, for example, regarding the physiological state of the user, the direction of the wearer's line of sight, iris recognition, and the like. In some embodiments, one camera assembly 630 is utilized for each eye and each eye may be monitored separately.

FIG. 7A illustrates an example of an emitted beam output by a waveguide. Although one waveguide is shown (using a perspective view), other waveguides in the waveguide assembly 260 (FIG. 6) may function as well. The light 640 is input into the waveguide 270 at the input surface 460 of the waveguide 270 and propagates in the waveguide 270 by TIR. Through interaction with the diffraction features, the light exits the waveguide as an exit beam 650. The exit beam 650 replicates the exit pupil from the projector device, which projects the image into the waveguide. Any one of the emitted beams 650 includes a subpart of the total energy of the input light 640. Also, in a perfectly efficient system, the sum of the energies in all the emitted beams 650 will be equal to the energy of the input light 640. The emitted beam 650 is illustrated as being substantially parallel in FIG. 7A, but as discussed herein, a certain amount of refractive power depends on the depth plane associated with the waveguide 270. , May be granted. The parallel emission beam externally couples the light and appears to be set on a depth plane at a long distance (eg, optical infinity) from the eye 210, forming an image, a waveguide with externally coupled optical elements. Can be shown. Other waveguides or other sets of externally coupled optics may output a more divergent, emitted beam pattern, as shown in FIG. 7B, which allows the eye 210 to adjust its perspective to a closer distance. However, it requires focus on the retina and will be interpreted by the brain as light from a distance closer to the eye 210 than optical infinity.

In some embodiments, a full-color image may be formed in each depth plane by overlaying the image on each of the primary colors (eg, three or more primary colors such as red, green, and blue). FIG. 8 illustrates an embodiment of a stacked waveguide assembly, where each depth plane contains an image formed using a plurality of different primary colors. The illustrated embodiments show depth planes 240a-240f, but more or less depth is also considered. Each depth plane contains three or more primary colors associated with it, including a first image of the first color G, a second image of the second color R, and a third image of the third color B. It may have an image. Different depth planes are shown in the figure by different diopter frequencies following the letters G, R, and B. The number following each of these letters indicates a diopter (1 / m), i.e., the reverse distance of the depth plane from the user, and each box in the figure represents an individual primary color image. In some embodiments, the exact location of the depth plane for different primary colors may vary to account for differences in eye focusing of light of different wavelengths. For example, different primary color images for a given depth plane may be placed on the depth plane corresponding to different distances from the user. Such an arrangement can increase visual acuity and user comfort, or reduce chromatic aberration.

In some embodiments, the light of each primary color may be output by a single dedicated waveguide, so that each depth plane may have multiple waveguides associated with it. In such an embodiment, each box in the figure can be understood to represent an individual waveguide so that the three waveguides display three primary color images per depth plane. It may be provided on a case-by-case basis. The waveguides associated with each depth plane are shown adjacent to each other in this drawing for ease of illustration, but in physical devices, all waveguides are one waveguide per level. It should be understood that they may be arranged in a stack with tubes. In some other embodiments, multiple primary colors may be output by the same waveguide, eg, so that only a single waveguide can be provided per depth plane.

With reference to FIG. 8, in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light, including yellow, magenta, and cyan, may also be used, or red, green, or blue. It may replace one or more of them. In some embodiments, features 320, 330, 340, and 350 are active or passive optical filters configured to selectively block or pass light from the ambient environment to the user's eye. It is also good.

References to a given light color throughout the present disclosure are to be understood to include light of one or more wavelengths within the wavelength range of light perceived by the user as that given color. .. For example, red light may contain light of one or more wavelengths in the range of about 620 to 780 nm, and green light may contain light of one or more wavelengths in the range of about 492 to 577 nm. Often, the blue light may include light of one or more wavelengths in the range of about 435-493 nm.

In some embodiments, the light source 530 (FIG. 6) may be configured to emit light of one or more wavelengths outside the user's visual perception range, such as IR and / or ultraviolet wavelengths. IR light can include light with wavelengths in the range of 700 nm to 10 μm. In some embodiments, the IR light can include near IR light with wavelengths in the range of 700 nm to 1.5 μm. In addition, the internal coupling, external coupling, and other optical redirection structures of the waveguide of the display 250 direct this light from the display to the user's eye 210, for example for imaging and / or user stimulating applications. It may be configured to direct and emit.

Now referring to FIG. 9A, in some embodiments, the light colliding with the waveguide may need to be redirected to internally couple the light into the waveguide. Internally coupled optics may be used to redirect and internally couple light into its corresponding waveguide. FIG. 9A illustrates a cross-sectional side view of an embodiment of a set of stacked waveguides 660, each including an internally coupled optical element. Each waveguide may be configured to output light of one or more different wavelengths or one or more different wavelength ranges. The stack 660 may correspond to the stack 260 (FIG. 6), and the illustrated waveguide of the stack 660 may correspond to a part of a plurality of waveguides 270, 280, 290, 300, 310. It is good, but the light from one or more of the image input devices 360, 370, 380, 390, 400 is guided from a position or orientation that requires the light to be redirected for internal coupling. Please understand that it is put into.

The illustrated set 660 of stacked waveguides includes waveguides 670, 680, and 690. Each waveguide contains an associated internally coupled optical element (which may also be referred to as an optical input area on the waveguide), for example, the internally coupled optical element 700 is the main surface of the waveguide 670 (eg, top). Placed on the main surface), the internally coupled optical element 710 is placed on the main surface of the waveguide 680 (eg, the upper main surface) and the internally coupled optical element 720 is placed on the main surface of the waveguide 690 (eg, the main surface). , Upper main surface). In some embodiments, one or more of the internally coupled optical elements 700, 710, 720 may be placed on the bottom main surface of the individual waveguides 670, 680, 690 (particularly). One or more internally coupled optical elements are reflective optical elements). As shown, even if the internally coupled optics 700, 710, 720 are placed on the upper main surface (or above the next lower waveguide) of its individual waveguides 670, 680, 690. Often, in particular, those internally coupled optics are transmissive optics. In some embodiments, the internally coupled optical elements 700, 710, 720 may be located within the body of the separate waveguides 670, 680, 690. In some embodiments, as discussed herein, the internally coupled optical elements 700, 710, 720 selectively re-wavelength one or more lights while transmitting other wavelengths of light. It is wavelength-selective to direct. Although illustrated on one side or corner of the individual waveguides 670, 680, 690, the internally coupled optical elements 700, 710, 720, in some embodiments, are the individual waveguides 670, 680, 690. It should be understood that they may be located within other areas.

As shown, the internally coupled optical elements 700, 710, 720 may be offset laterally from each other. In some embodiments, each internally coupled optic may be offset to receive light rather than letting its light pass through another internally coupled optic. For example, each internally coupled optical element 700, 710, 720 may be configured to receive light from different image input devices 360, 370, 380, 390, and 400, as shown in FIG. It may be separated (eg, laterally separated) from the other internally coupled optical elements 700, 710, 720 so that it does not substantially receive from the other internally coupled optical elements 700, 710, 720.

Each waveguide also contains an associated light dispersion element, eg, the light dispersion element 730 is placed on the main surface of the waveguide 670 (eg, the upper main surface) and the light dispersion element 740 is a guide. The wave guide 680 is placed on the main surface (eg, the upper main surface) and the light dispersion element 750 is placed on the main surface of the waveguide 690 (eg, the upper main surface). In some other embodiments, the light dispersion elements 730, 740, 750 may be located on the bottom main surface of the associated waveguides 670, 680, 690, respectively. In some other embodiments, the light dispersion elements 730, 740, 750 may be located both on the top and bottom major surfaces of the associated waveguides 670, 680, 690, respectively. , Or the light dispersion elements 730, 740, 750 may be located on different top and bottom main surfaces within different associated waveguides 670, 680, 690, respectively.

The waveguides 670, 680, 690 may be separated and separated by, for example, a gas, liquid, and / or solid layer of material. For example, as shown, layer 760a may separate waveguides 670 and 680, and layer 760b may separate waveguides 680 and 690. In some embodiments, the layers 760a and 760b are formed from a low index of refraction material (ie, a material having a lower index of refraction than the material forming the immediate vicinity of the waveguides 670, 680, 690). Preferably, the refractive index of the material forming the layers 760a, 760b is at least 0.05 or at least 0.10 less than the refractive index of the material forming the waveguides 670, 680, 690. Advantageously, the lower index layers 760a, 760b facilitate the TIR of light through the waveguides 670, 680, 690 (eg, the TIR between the top and bottom major surfaces of each waveguide). It may function as a cladding layer. In some embodiments, the layers 760a, 760b are formed from air. Although not shown, it should be understood that the top and bottom of the illustrated set 660 of the waveguide may include the nearest cladding layer.

Preferably, for ease of manufacture and other considerations, the materials forming the waveguides 670, 680, 690 are similar or identical, and the materials forming layers 760a, 760b are similar or identical. Is. In other embodiments, the materials forming the waveguides 670, 680, 690 may differ between one or more waveguides, or the materials forming the layers 760a, 760b may still be the various materials described above. It may be different while maintaining the refractive index relationship of.

Continuing with reference to FIG. 9A, the rays 770, 780, 790 are a set of waveguides 660.
Incident to. The rays 770, 780, 790 may be emitted into the waveguide 670, 680, 690 by one or more image input devices 360, 370, 380, 390, 400 (FIG. 6).

In some embodiments, the rays 770, 780, 790 have different properties (eg, different wavelengths or different wavelength ranges) that can accommodate different colors. The internally coupled optical elements 700, 710, and 720 redirect the incident light so that the light propagates by TIR through a separate one of the waveguides 670, 680, and 690, respectively.

For example, the internally coupled optical element 700 may be configured to selectively redirect the ray 770 having a first wavelength or wavelength range. Similarly, the transmitted light beam 780 collides with and is redirected to an internally coupled optical element 710 configured to redirect light in a second wavelength or wavelength range. Similarly, the ray 790 is redirected by an internally coupled optical element 720 configured to selectively redirect light in a third wavelength or wavelength range.

With reference to FIG. 9A continuously, the rays 770, 780, 790 are redirected to propagate through the corresponding waveguides 670, 680, 690. That is, the internally coupled optical elements 700, 710, 720 of each waveguide redirect the light into its corresponding waveguide 670, 680, 690 and internally couple the light into the corresponding waveguide. do. The rays 770, 780, 790 are redirected at an angle that allows the light to propagate through the separate waveguides 670, 680, 690 by TIR. Rays 770, 780, 790 propagate through separate waveguides 670, 680, 690 by TIR until they interact with the corresponding light dispersion elements 730, 740, 750 of the waveguide.

Here, with reference to FIG. 9B, a perspective view of an embodiment of the plurality of stacked waveguides of FIG. 9A is illustrated. As mentioned above, the rays 770, 780, 790 are internally coupled by the internally coupled optical elements 700, 710, 720, respectively, and then propagated by TIR in the waveguides 670, 680, 690, respectively. The rays 770, 780, 790 then interact with the light dispersion elements 730, 740, 750, respectively. The light dispersion elements 730, 740, and 750 redirect the rays 770, 780, and 790 so that they propagate toward the outer-coupled optical elements 800, 810, and 820, respectively.

In some embodiments, the light dispersion elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPE redirects the light to the outer coupling optics 800, 810, 820 and also the light dispersion elements 730, 740, 750 as they propagate to the outer coupling optics. By sampling the rays 770, 780, 790 at many locations across it, we do both to dilate the pupil associated with the main light. In some embodiments (eg, if the exit pupil is already of the desired size), the light dispersion elements 730, 740, 750 may be omitted and the internally coupled optical elements 700, 710, 720 may emit light. It may be configured to redirect directly to the outer coupling optics 800, 810, 820. For example, referring to FIG. 9A, the light dispersion elements 730, 740, 750 may be replaced with externally coupled optical elements 800, 810, 820, respectively. In some embodiments, the externally coupled optical elements 800, 810, 820 redirect light from the waveguide towards the user's eye 210 (FIG. 7), an exit pupil (EP) or exit pupil expander ( EPE). The OPE may be configured to increase the size of the eyebox on at least one axis, and the EPE may be configured to increase the eyebox on an axis that intersects (eg, is orthogonal to) the axis of the OPE. May be good.

Therefore, referring to FIGS. 9A and 9B, in some embodiments, a set of waveguides 66
0 indicates the waveguides 670, 680, 690, the internally coupled optical elements 700, 710, 720, the optical dispersion elements (eg, OPE) 730, 740, 750, and the outer coupled optical elements (eg, for example) for each primary color. EPE) 800, 810, 820 and the like. The waveguides 670, 680, 690 may be stacked with a gap / cladding layer between each one. Internally coupled optical elements 700, 710, 720 direct incident light (using different internally coupled optical elements that receive light of different wavelengths) into the corresponding waveguide. Light then propagates at angles that support TIR within the separate waveguides 670, 680, 690. Since TIR occurs only over a certain angle range, the range of propagation angles of the rays 770, 780, 790 is limited. The range of angles that support the TIR can be considered in such an embodiment as the angular limit of the field of view that can be displayed by the waveguides 670, 680, 690. In the embodiments shown, the light beam 770 (eg, blue light) is internally coupled by a first internally coupled optical element 700 in the manner described above and then of the waveguide while traveling along the waveguide. Continuing to reciprocate from the surface, the light dispersive element (eg, OPE) 730 sequentially samples it to create additional replicating rays directed towards the outer coupled optics (eg, EPE) 800. .. Rays 780 and 790 (eg, green and red light, respectively) pass through the waveguide 670 and the rays 780 collide on the internally coupled optical element 710, thereby being internally coupled. The ray 780 will then propagate through the waveguide 680 via the TIR to its light dispersion element (eg, OPE) 740 and then to the externally coupled optical element (eg, EPE) 810. Finally, the light beam 790 (eg, red light) passes through the waveguides 670, 680 and collides with the optical internally coupled optical element 720 of the waveguide 690. The light internally coupled optical element 720 internally couples the light beam 790 such that the light beam propagates by TIR to the light dispersion element (eg, OPE) 750 and then by TIR to the externally coupled optical element (eg, EPE) 820. do. The externally coupled optical element 820 then finally externally couples the ray 790 to the user, and the viewer also receives the externally coupled light from the other waveguides 670, 680.

FIG. 9C illustrates a top-down plan view of an embodiment of the plurality of stacked waveguides of FIGS. 9A and 9B. As shown, the waveguides 670, 680, 690 are vertically aligned with the associated optical dispersion elements 730, 740, 750 and the associated externally coupled optical elements 800, 810, 820 of each waveguide. May be done. However, as discussed herein, the internally coupled optical elements 700, 710, 720 are not vertically aligned. Rather, the internally coupled optics may be non-overlapping (eg, laterally spaced, as seen in the top and bottom views). This non-overlapping spatial arrangement facilitates the introduction of light from different sources into different waveguides on a one-to-one basis, whereby the specific light source is uniquely optically coupled to the specific waveguide. Can make it possible. In some embodiments, sequences that include non-overlapping, spatially separated internally coupled optics can be referred to as a shift pupil system, and the internally coupled optics within these sequences correspond to subpuppies. Can be.

FIG. 10 is a perspective view of an exemplary AR eyepiece waveguide stack 1000. The eyepiece waveguide stack 1000 may include a world-side cover window 1002 and an eye-side cover window 1006 to protect one or more eyepiece waveguides 1004 located between the cover windows. In other embodiments, one or both of the cover windows 1002, 1006 may be omitted. As already discussed, the eyepiece waveguide 1004 may be arranged in a stratified configuration. The eyepiece waveguide 1004 may be coupled together, for example, each individual eyepiece waveguide may be coupled to one or more adjacent eyepiece waveguides. In some embodiments, the waveguide 1004 may be coupled with an edge seal (such as the edge seal 1108 shown in FIG. 11) so that adjacent eyepiece waveguides 1004 do not come into direct contact with each other.

The eyepiece waveguide 1004 can be made from a substrate material that is at least partially transparent, such as glass, plastic, polycarbonate, sapphire, etc., respectively. The selected material may have a refractive index greater than 1.4, eg, greater than 1.6, or greater than 1.8, facilitating light induction. The thickness of each eyepiece waveguide substrate may be, for example, 325 microns or less, but other thicknesses can also be used. Each eyepiece waveguide can include one or more inner coupling regions, an optical dispersion region, an image expansion region, and an outer coupling region, which can be on or within each waveguide substrate 902. It may consist of the diffraction features formed.

Although not shown in FIG. 10, the eyepiece waveguide stack 1000 can include a physical support structure for supporting it in front of the user's eye. In some embodiments, the eyepiece waveguide stack 1000 is part of a head-mounted display system 60, as illustrated in FIG. Generally, the eyepiece waveguide stack 1000 is supported such that the outer coupling region is directly in front of the user's eye. It should be appreciated that FIG. 10 illustrates only a portion of the eyepiece waveguide stack 1000 that corresponds to one of the user's eyes. The finished eyepiece may include a mirror image of the same structure, possibly with two halves separated by a nasal pad.

In some embodiments, the eyepiece waveguide stack 1000 can project color image data from multiple depth planes into the user's eye. The image data displayed by each individual eyepiece waveguide 1004 in the eyepiece 1000 may correspond to a selected color component of the image data for the selected depth plane. For example, the eyepiece waveguide stack 1000 includes six eyepiece waveguides 1004 and thus projects color image data (eg, consisting of red, green, and blue components) corresponding to two different depth planes. That is, one eyepiece waveguide 1004 per color component per depth plane. Other embodiments may include eyepiece waveguide 1004 for more or less color components and / or more or less depth planes.

FIG. 11 is a partial cross-sectional view of an exemplary eyepiece waveguide stack 1100 with an edge seal structure 1108 for supporting the eyepiece waveguide 1104 in a stacked configuration. The edge seal structure 1108 aligns the eyepiece waveguides 1104 and separates them from each other using air space or another material placed between them. Although not shown, the edge seal structure 1108 can extend around the entire circumference of the stacked waveguide configuration. In FIG. 11, the separation between the eyepiece waveguides is 0.027 mm, but other distances are also possible.

In the illustrated embodiment, two eyepieces designed to display red image data, one for a 3 m depth plane and the other for a 1 m depth plane. There is a waveguide 1104. (Again, the divergence of the beam of light output by the eyepiece waveguide 1104 can cause the image data to appear to originate from a depth plane located at a particular distance.) Similarly, one is 3 m deep. Two eyepiece waveguides 1104 designed to display blue image data, one for the plane and the other for the 1 m depth plane, and one for the 3 m depth plane. There are two eyepiece waveguides 1104 designed to display green image data, one for, and the other for a 1 m depth plane. Each of these six eyepiece waveguides 1104 is shown to be 0.325 mm thick, but other thicknesses are also considered possible.

The world side cover window 1102 and the eye side cover window 1106 are also shown in FIG. These cover windows can be, for example, 0.330 mm thick. Considering the thickness of the six eyepiece waveguides 1104, the seven air gaps, the two cover windows 1102, 1106, and the edge seal 1108, the total thickness of the illustrated eyepiece waveguide stack 1100 is 2. It is 8 mm.

(K-space representation of AR eyepiece waveguide)
12A and 12B illustrate the top view of the eyepiece waveguide 1200 during operation when projecting an image towards the user's eye 210. The image can first be projected from the image plane 1207 towards the entrance pupil 1208 of the eyepiece waveguide 1200 using a projection lens 1210 or some other projector device. Each image point (eg, an image pixel or part of an image pixel) has a corresponding input beam of light (eg, 1202a, 1204a, 1206a), which is the optics of the entrance pupil 1208 (eg, projector lens 1210). Propagate in a specific direction at a specific angle to the axis). Although illustrated as light rays, the light input beams 1202a, 1204a, 1206a may be collimated beams with diameters of a few millimeters or less when they are incident on the eyepiece waveguide 1200, for example. ..

In FIGS. 12A and 12B, the central image point corresponds to the input beam 1204a, which is illustrated with a solid line. The right image point corresponds to the input beam 1202a, illustrated with a dashed line. The left image point, illustrated using the chain line, corresponds to the input beam 1206a. To clarify the illustration, only three input beams 1202a, 1204a, 1206a are shown at the entrance pupil 1208, but a typical input image corresponds to different image points in the two-dimensional image plane, x-. It will contain many input beams propagating over a range of angles in both the directional and y-directions.

There is a unique correspondence between the various propagation angles of the input beam (eg, 1202a, 1204a, 1206a) at the entrance pupil 1208 and the individual image points on the image plane 1207. The eyepiece waveguide 1200 all internally couple the input beams (eg, 1202a, 1204a, 1206a) and combine them in a distributed fashion, while substantially maintaining the correspondence between the image point and the beam angle. It can be designed to replicate through space, guide them, and form an exit pupil 1210, which is larger than the entrance pupil 1208 and consists of the duplicated beams. The eyepiece waveguide 1200 can convert a given input beam of light (eg 1202a), which propagates into many replicated beams (eg 1202b) at a particular angle. Is output across the exit pupil 1210 at an angle that is substantially uniquely correlated with that particular input beam and its corresponding image point. For example, the duplicate output beam corresponding to each input beam may exit the eyepiece waveguide 1200 at substantially the same angle as the corresponding input beam.

As shown in FIGS. 12A and 12B, the light input beam 1204a corresponds to the central image point on the image plane 1207 and is converted into a set of duplicate output beams 1204b, shown by solid lines, which are eyepiece waveguides. It is aligned with the optical axis perpendicular to the exit pupil 1210 of the tube 1200. The input beam 1202a of light corresponding to the right image point on the image plane 1207 is transformed into a set of duplicate output beams 1202b, shown by the dashed lines, which arise from somewhere within the right portion of the user's field of view. It exits from the eyepiece waveguide 1200 at a propagation angle that appears as if it were. Similarly, the input beam 1206a of light corresponding to the left image point on the image plane 1207 is converted into a set of duplicate output beams 1206b, represented by a chain line, where they are within the left portion of the user's field of view. It exits from the eyepiece waveguide 1200 at a propagation angle that appears to arise from. The larger the range of the input beam angle and / or the output beam angle, the larger the field of view (FOV) of the eyepiece waveguide 1200.

For each image, there is a set of duplicated output beams (eg, 1202b, 1204b, 1206b), i.e., one set of duplicated beams per image point, which is output at different angles across the exit pupil 1210. To. Individual output beams (eg 1202b, 1204)
b, 1206b) can be collimated respectively. The set of output beams corresponding to a given image point may consist of beams propagating along a parallel path (as shown in FIG. 12A) or a divergent path (as shown in FIG. 12B). In each case, the specific propagation angle of the set of duplicate output beams depends on the location of the corresponding image point on the image plane 1207. FIG. 12A illustrates the case where each set of output beams (eg, 1202b, 1204b, 1206b) consists of beams propagating along parallel paths. This results in the image being projected as if it originated from optical infinity. This extends from the peripheral output beam 1202b, 1204b, 1206b toward the optical infinity on the world side of the eyepiece waveguide 1200 (opposite the location of the user's eye 210) in FIG. 12A. It is represented by a thin line. FIG. 12B illustrates the case where each set of output beams (eg, 1202b, 1204b, 1206b) consists of beams propagating along a divergence path. This results in the image being projected as if it originated from a virtual depth plane with a distance closer than optical infinity. This is represented in FIG. 12B by a thin line extending from the peripheral output beam 1202b, 1204b, 1206b toward a point on the world side of the eyepiece waveguide 1200.

Again, each set of duplicate output beams (eg, 1202b, 1204b, 1206b) has a propagation angle that corresponds to a particular image point on the image plane 1207. For a set of duplicate output beams propagating along parallel paths (see FIG. 12A), the propagating angles of all beams are the same. However, in the case of a set of duplicate output beams propagating along a divergence path, the individual output beams can propagate at different angles, which are the angles at which they create an aggregate divergent wavefront and of the set of beams. They are interrelated in that they appear to originate from common points along the axis (see Figure 12B). This axis defines the angle of propagation for a set of divergent output beams and corresponds to a particular image point on the image plane 1207.

The various beams of light incident on the eyepiece waveguide 1200, propagating in the eyepiece lens waveguide, and exiting the eyepiece lens waveguide all have one or more wave vectors, i.e., the direction of propagation of the beam. Explained using the k-vector. K-space is an analytical framework that associates k-vectors with geometric points. In k-space, each point in space corresponds to a unique k-vector, which in turn can represent a beam or ray of light with a particular propagation direction. This allows input and output beams with their corresponding propagation angles to be understood as a set of points in k-space (eg, a rectangle). Diffraction features that change the direction of propagation of a light beam as it travels through the eyepiece can be understood in k-space as simply translating the location of a set of k-space points that make up the image. This new translated k-space location corresponds to a new set of k-vectors, which in turn represents a new propagation angle of the beam or ray after interaction with the diffraction features.

The operation of the eyepiece waveguide can be understood by the mode of moving a set of points, such as points inside a k-space rectangle, in k-space, corresponding to the projected image. This is in contrast to the more complex ray trace diagrams that can be used to illustrate the beam and its propagation angle. K-space is therefore an effective tool for explaining the design and operation of eyepiece waveguides. The following discussion describes the k-space representation of the features and functions of various AR eyepiece waveguides.

FIG. 13A illustrates a k-vector 1302 that can be used to represent the propagation direction of a ray or light beam. The particular illustrated k-vector 1302 represents a plane wave with a plane wave plane 1304. The k-vector 1302 points to the direction of propagation of the ray or beam it represents. The magnitude, or length, of the k-vector 1302 is defined by the wavenumber k. The distributed expression ω = ck associates the angular frequency ω of light, the speed of light c, and the wave number k. (In a vacuum, the speed of light is equal to the constant c of the speed of light. However, in the medium, the speed of light is inversely proportional to the refractive index of the medium. Therefore, in the medium, the equation is k =. Note that by definition, k = 2π / λ and ω = 2πf, where f is the speed of light (eg, in Hertz). As is clear from this equation, a light beam with a higher angular frequency ω has a larger wavenumber and therefore a larger magnitude k-vector (assumed to be the same propagating medium). For example, assuming the same propagation medium, the blue light beam has a larger k-vector than the red light beam.

FIG. 13B illustrates a ray 1301 corresponding to a k-vector 1302 in a planar waveguide 1300. The waveguide 1300 may represent any of the waveguides described herein and may be part of an eyepiece for an AR display system. The waveguide 1300 can guide a ray having a certain k-vector via total internal reflection (TIR). For example, as shown in FIG. 13B, the ray 1301 illustrated by the k-vector 1302 is directed towards the upper surface of the waveguide 1300 at an angle. If the angle is not very steep, as controlled by Snell's law, the ray 1301 reflects off the upper surface of the waveguide 1300 at an angle equal to the angle of incidence and then the lower side of the waveguide 1300. It will propagate downwards towards the surface, where it will again reflect back towards the upper surface. The ray 1301 will propagate in the waveguide 1300 in a guided manner and will continue to reciprocate and reflect between its upper and lower surfaces.

FIG. 13C illustrates an acceptable k-vector for light at a given angular frequency ω propagating in a non-boundary homogeneous medium with a refractive index n. The length of the illustrated k-vector 1302, i.e., the magnitude k, is equal to the index of refraction of the medium n × the angular frequency ω of the light, which is divided by the constant c of the speed of light. For a ray or beam with a given angular frequency ω propagating in a homogeneous medium with a refractive index n, the magnitudes of all acceptable k-vectors are the same. Also, for unguided propagation, all propagation directions are allowed. Therefore, the manifold in k-space that defines all acceptable k-vectors is the hollow sphere 1306, and the size of the sphere depends on the angular frequency of the light and the index of refraction of the medium.

FIG. 13D illustrates an acceptable k-vector for light at a given angular frequency ω propagating in a homogeneous planar waveguide medium with a refractive index n. Within the non-boundary medium, all acceptable k-vectors are on the hollow sphere 1306, but on a plane (eg, xy plane) to determine the acceptable k-vectors in the planar waveguide. An acceptable k-vector sphere 1306 can be projected. This results in a solid disk 1308 in projected k-space representing a k-vector that can propagate within a planar waveguide. As shown in FIG. 13D, all k-vectors that can propagate within a planar waveguide in the xy plane (eg, waveguide 1300) are all light components of the k-vector in the xy plane. The refractive index of the medium divided by the constant c of the speed of light is n × the angular frequency of light ω or less.

を使用して求められ得、選定される符号は、波がページの内外に伝搬するかどうかを決定する。屈折率ｎを伴う均質媒体内を伝搬する、所与の角周波数ωの全ての光波は、同一大きさｋ－ベクトルを有するため、そのｘ－ｙ成分が中実円板１３０８の半径にサイズがよ
り近いｋ－ベクトルを伴う、光波は、伝搬のより小さいｚ－成分を有する（図１３Ｂに関して議論されるように、ＴＩＲのために必要なあまり急峻ではない伝搬角度をもたらす）一方、そのｘ－ｙ成分が中実円板１３０８の中心のより近くに位置するｋ－ベクトルを伴う、光波は、伝搬のより大きいｚ－成分を有する（ＴＩＲし得ない、より急峻な伝搬角度をもたらす）。故に、ｋ－空間の全ての言及は、その中で２－次元ｋ－平面が導波管の平面に対応する、投影されたｋ－空間を指す（別様に文脈から明白ではない限り）。すなわち、導波管の表面間の伝搬方向が、明示的に述べられない限り、議論および図面は、概して、導波管の表面と平行な方向のみを検討する。さらに、ｋ－空間をプロットするとき、典型的には、プロットがω／ｃに事実上正規化されるように、自由空間円板半径を１に正規化することが最も便宜的である。 All points in the solid disk 1308 correspond to the k-vectors of the wave that can propagate in the waveguide (provided that all of these k-vectors are discussed below with respect to FIG. 13E. , Does not result in guided propagation within the waveguide). At each point in the solid disk 1308, there are two permissible waves. That is, one is accompanied by a z-component of propagation toward the inside of the page, and the other is accompanied by a z-component of propagation outward from the page. Therefore, the out-of-plane component _kz of the k-vector is an equation.

The sign that can be determined and selected using is determine whether the wave propagates in and out of the page. Since all light waves at a given angular frequency ω propagating in a homogeneous medium with a refractive index n have the same magnitude k-vector, their xy component is sized to the radius of the solid disk 1308. A light wave with a closer k-vector has a smaller z-component of propagation (which, as discussed for FIG. 13B, results in the less steep propagation angle required for TIR), while its x-. A light wave with a k-vector with the y component located closer to the center of the solid disk 1308 has a larger z-component of propagation (which results in a steeper propagation angle that cannot be TIR). Therefore, all references to k-space refer to the projected k-space in which the 2-dimensional k-plane corresponds to the plane of the waveguide (unless otherwise obvious from the context). That is, unless the direction of propagation between the surfaces of the waveguide is explicitly stated, discussions and drawings generally consider only the direction parallel to the surface of the waveguide. Moreover, when plotting k-spaces, it is typically most convenient to normalize the free space disk radius to 1 so that the plot is effectively normalized to ω / c.

を有する、媒体（例えば、空気）によって物理的に囲繞される。図１３Ｄに関して議論されたばかりのように、ｘ－ｙ平面における平面導波管媒体内の許容波に対応するｋ－ベクトルは全て、その個別のｘ－ｙ成分がｋ－空間内の中実円板１３０８内にある、それらのｋ－ベクトルである。中実円板１３０８の半径は、導波管媒体の屈折率に比例する。したがって、図１３Ｅに戻って参照すると、屈折率ｎ_２＝１．５を有する平面導波管媒体内を伝搬し得る光波に対応する、ｋ－ベクトルは、その個別のｘ－ｙ成分がより大きい円板１３０８ａ内にあるものである。一方、屈折率ｎ_１＝１を有する周囲媒体内を伝搬し得る光波に対応する、ｋ－ベクトルは、その個別のｘ－ｙ成分がより小さい円板１３０８ｂ内にあるものである。その個別のｘ－ｙ成分が環１３１０の内側にある、全てのｋ－ベクトルは、導波管媒体内を伝搬し得るが、周囲媒体（例えば、空気）内を伝搬しない、それらの光波に対応する。これらは、図１３Ｂに関して説明されるように、全内部反射を介して導波管媒体内で誘導される、光波である。したがって、光線またはビームは、それらがｋ－空間環１３１０内にあるｋ－ベクトルを有する場合、ＡＲ接眼レンズの導波管内で誘導伝搬のみを受け得る。より大きい円板１３０８ａの外側のｋ－ベクトルを有する、伝搬光波は、禁止されることに留意されたい。すなわち、そのｋ－ベクトルがその領域内にある、伝搬する波は、存在しない（その領域内の波は、その伝搬方向に沿って、一定ではなく、エバネッセント減衰振幅を有する）。 FIG. 13E illustrates a ring 1310 in k-space corresponding to a k-vector of light waves that can be guided in a waveguide having a refractive index n ₂ (eg, n ₂ = 1.5). Waveguides have a lower index of refraction n ₁

Is physically surrounded by a medium (eg, air). As just discussed with respect to FIG. 13D, all k-vectors corresponding to the permissible waves in the planar waveguide medium in the xy plane are solid disks whose individual xy components are in k-space. Those k-vectors within 1308. The radius of the solid disk 1308 is proportional to the refractive index of the waveguide medium. Therefore, referring back to FIG. 13E, the k-vector, which corresponds to a light wave that can propagate in a planar waveguide medium with a refractive index of n ₂ = 1.5, has a larger individual xy component. It is in the disk 1308a. On the other hand, the k-vector corresponding to the light wave that can propagate in the ambient medium having a refractive index n ₁ = 1 is that the individual xy component is in the smaller disk 1308b. All k-vectors whose individual xy components are inside the ring 1310 correspond to those light waves that can propagate within the waveguide medium but not within the ambient medium (eg, air). do. These are light waves induced in the waveguide medium via total internal reflection, as described with respect to FIG. 13B. Thus, a ray or beam can only undergo guided propagation within the waveguide of an AR eyepiece if they have a k-vector within the k-space ring 1310. Note that propagating light waves with a k-vector outside the larger disk 1308a are prohibited. That is, there is no propagating wave whose k-vector is in that region (waves in that region are not constant along their propagation direction and have an evanescent damping amplitude).

内を伝搬する光ビームのｋ－ベクトルを接眼レンズ導波管のｋ－空間環１３１０の中に指向することができる。そのｋ－ベクトルが環１３１０内にある、任意の光波は、接眼レンズ導波管内で誘導方式において伝搬することができる。環１３１０の幅は、接眼レンズ導波管内で誘導され得る、ｋ－ベクトルの範囲、故に、伝搬角度の範囲を決定する。したがって、ｋ－空間環１３１０の幅は、典型的には、接眼レンズ導波管によって投影され得る、最大視野（ＦＯＶ）を決定すると考えられている。環１３１０の幅は、それ自体が接眼レンズ導波管媒体の屈折率ｎ_２に部分的に依存する、より大きい円板１３０８ａの半径に依存するため、接眼レンズＦＯＶを増加させるための１つの技法は、より大きい屈折率（接眼レンズ導波管を囲繞する媒体の屈折率と比較して）を伴う接眼レンズ導波管媒体を使用することである。しかしながら、材料コスト等、ＡＲ接眼レンズ内で使用され得る導波
管媒体の屈折率に関する実践的限界が存在する。これは、ひいては、ＡＲ接眼レンズのＦＯＶに実践的限界を課すと考えられている。しかし、本明細書に説明されるように、より大きいＦＯＶを可能にするためにこれらの限界を克服するために使用され得る、技法が存在する。 The various AR eyepiece waveguides described herein use diffraction features such as diffraction structures to internally couple light and free space (eg, from a projector).

The k-vector of the light beam propagating within can be directed into the k-space ring 1310 of the eyepiece waveguide. Any light wave whose k-vector is in ring 1310 can propagate in an inductive manner within the eyepiece waveguide. The width of the ring 1310 determines the range of k-vectors that can be guided within the eyepiece waveguide, and thus the range of propagation angles. Therefore, it is believed that the width of the k-space ring 1310 typically determines the maximum field of view (FOV) that can be projected by the eyepiece waveguide. One technique for increasing the eyepiece FOV because the width of the ring 1310 depends on the radius of the larger disc 1308a, which itself partially depends _on the refraction n2 of the eyepiece waveguide medium. Is to use an eyepiece waveguide medium with a higher refraction factor (compared to the refractive index of the medium surrounding the eyepiece waveguide). However, there are practical limitations regarding the refractive index of the waveguide medium that can be used in the AR eyepiece, such as material cost. This, in turn, is believed to impose practical limits on the FOV of AR eyepieces. However, as described herein, there are techniques that can be used to overcome these limitations to enable greater FOV.

The radius of the larger disc 1308a in FIG. 13E also depends on the angular frequency ω of the light and the width of the ring 1310, and thus on the color of the light, but this is any given angle corresponding to the FOV. Since the range is similarly scaled in direct proportion to the angular frequency, it does not imply that the FOV supported by the eyepiece waveguide is greater for light with higher angular frequencies.

FIG. 13F shows a k-space schematic similar to that depicted in FIG. 13E. The k-space schematic shows a smaller disk 1308b corresponding to the acceptable k-vector in the first medium of refractive index n ₁ and in the second medium of refractive index n ₂ (n ₂ > n ₁ ). Shows the larger disk 1308a and the ring 1310 between the outer boundaries of the smaller disk 1308a and the larger disk 1308b, corresponding to the acceptable k-vector of. All k-vectors in the width 1342 of the ring 1310 correspond to the induced propagation angle, but less than all of the k-vectors in the width 1342 of the ring 1310 are to be used when displaying the image. It is possible that it may be sufficient.

FIG. 13F also shows a waveguide 1350 with two guided beams shown in comparison to each other. The first light beam has a first k-vector 1344a near the outer edge of ring 1310. The first k-vector 1344a corresponds to the first TIR propagation path 1344b shown in the cross-sectional view of the waveguide 1350 having a refractive index n ₂ surrounded by air having a refractive index n ₁ . A second light beam with a second k-vector 1346a closer to the center of the k-space ring 1310 is also shown. The second k-vector 1346a corresponds to the second TIR propagation path 1346b in the waveguide 1350. The waveguide 1350 may include a diffraction grating 1352 on or within the waveguide 1350. When the light beam encounters the surface of the waveguide 1350 with the grating 1352, an interaction occurs, which causes a sample of light beam energy to move out of the waveguide while the beam continues to TIR inside the waveguide. Can be sent. The angle at which the light beam propagates in the TIR through the waveguide determines the density of reflected events per unit length, i.e., the number of bounces, with respect to the surface of the waveguide 1350 with the grating 1352. Returning to the example of light beam comparison, the first light beam in the first TIR propagation path 1344b is reflected four times from the surface of the waveguide with the grating 1352 and 4 over the length of the grating 1352. While producing one ejection pupil 1354 (illustrated with a solid line), the second light beam within the second TIR propagation path 1346b is from the surface of the waveguide with the grating 1352 over the same or similar distances. It reflects 10 times and traverses the length of the grating 1352 to produce 10 ejection pupils 1356 (shown with broken lines).

In practice, the output beam, ie, the exit pupil spacing will be constrained to or within a preselected range, and the content projected to the user will be visible from any position within the predefined eyebox. It may be desirable to ensure that. By using this information, the width 1342 of the ring 1310 can be limited to a subset of the k-vectors 1344 to which this constraint applies, and the angle of the glaze incident angle can be excluded so that it is not included in the design calculation. It is possible. Angles greater than or less than subset 1344 may also be acceptable, depending on the desired performance, grating design, and other optimization factors. Similarly, in some embodiments, the k-vector corresponding to the propagation angle, which is too steep with respect to the surface of the waveguide and provides too much interaction with the grating 1352, is also from use. It may be excluded. In such an embodiment, the width 1342 of the ring 1310 is reduced by effectively moving the usable angle boundary radially outward from the boundary between the larger disc 1308a and the smaller disc 1308b. Can be. Any design of the eyepiece waveguides disclosed herein can be adjusted by thus constraining the width 1310 of the k-space ring.

As described above, the k-vector in the ring 1310, which corresponds to the semi-optimal TIR propagation path, may be omitted from its use in eyepiece design calculations. Alternatively, a k-vector corresponding to a TIR propagation path with an angle of angle of incidence that is too hazy, and thus a density of too few reflection events on the surface of a waveguide with a diffraction grating, is described herein. It may be compensated using various techniques. One technique is to use an internally coupled lattice to direct a portion of the field of view (FOV) of the incident image to two different areas of the k-space ring 1310. In particular, the incident image is taken from the first side of the k-space ring 1310 represented by the first group of k-vectors and the second side of the k-space ring 1310 represented by the second group of k-vectors. It may be advantageous to point to the side, with the first and second sides of the k-space ring 1310 substantially facing each other. For example, the first group of k-vectors may correspond to the FOV rectangle of the k-vector on the left side of ring 1310, and the second group of k-vectors may correspond to the FOV rectangle of the k-vector on the right side of ring 1310. Can be accommodated. The left FOV rectangle has its left edge near the outer edge of the larger disk 1308a and corresponds to the k-vector angle near the glaze incident angle. Light at the main edge will produce a sparse exit pupil. However, the same left edge of the right FOV rectangle, located to the right of ring 1310, will be closer to the center of the larger disk 1308a. Light at the same left edge of the right FOV rectangle will have a dense exit pupil. Thus, when the left and right FOV rectangles are recombinated and exit from the waveguide towards the user's eye to produce an image, a sufficient number of exit pupils are produced in all areas of the field of view.

Diffractive features such as diffraction grids are used to couple light into the eyepiece waveguide and outward from the eyepiece waveguide and / or to change the direction of light propagation within the eyepiece waveguide. Can be done. In k-space, the effect of a grating on a ray or beam of light represented by a particular k-vector is determined by the addition of a vector of k-vector components in the plane of the grating with a lattice vector. .. The size and direction of the grating vector depends on the specific properties of the diffraction grating. FIGS. 13G, 13H, and 13I illustrate the action of the grating on the k-vector in k-space.

FIG. 13G illustrates a top view of the grating 1320 and some of its associated k-space grating vectors (G _{- 2} , G _{- 1} , G1, G2). The diffraction grating 1320 is oriented in the xy plane, and FIG. 13G shows a diagram of the grating from the line of sight of a ray or beam incident on it from the z- direction. The grating 1320 has an associated set of k-space grating vectors (eg, G _{- 2} , G _{- 1} , G1, G2) oriented in the same plane as the grating. The G ₁ and G _-1 lattice vectors each correspond to a ± 1 diffraction order, while the G ₂ and G _-2 lattice vectors each correspond to a ± 2 diffraction order. The grating vector for ± 1 diffraction order points in the opposite direction (along the periodic axis of the grating) and has an equal magnitude that is inversely proportional to the period Λ of the grating 1320. Therefore, a diffraction grating with a finer pitch has a larger grating vector. The lattice vector for ± 2 diffraction order also points in the opposite direction and has twice the magnitude of the lattice vector for ± 1 diffraction order. Lattice vectors for additional higher diffraction orders may also exist, but they are not shown. For example, the magnitude of the lattice vector with respect to the ± 3 diffraction order continues to be 3 times the lattice vector with respect to the ± 1 diffraction order. _The basic lattice vector G1 is simply determined by the periodicity (direction and pitch) of the lattice, while the composition of the lattice (eg, surface profile, material, layer structure) is other than the lattice such as diffraction efficiency and diffraction phase. Note that it can affect the characteristics of. Since all harmonics of the reciprocal lattice vector (eg G _{- 1} , G2, G _{-2 ,} etc.) are simply integral multiples of the basic G1, all diffraction directions of the lattice are simply the period of the lattice. Determined by gender. The action of the grating 1320 is to add the grating vector to the in-plane component of the k-vector corresponding to the incident ray or beam. This is shown in FIG. 13H.

FIG. 13H illustrates the side view of the grating 1320 and its effect in k-space over the k-vector 1302 corresponding to the normal incident ray or beam of light. The grating 1320 diffracts an incident ray or a beam of light to one or more diffraction orders. A new ray or beam of light at each of these diffraction orders is represented by a new k-vector (eg, 1302a-e). These new k-vectors (eg, 1302a-e) are obtained by adding a vector of in-plane components of the k-vector 1302 with each of the lattice vectors (eg G _{- 2} , G _{- 1} , G1, G2). It is determined. In the illustrated case of a normal incident ray or a beam of light, the k-vector 1302 has no component in the xy plane of the diffraction grating. Thus, the effect of the grating 1320 is to create one or more new diffracted rays or beams of light whose k-vector (eg, 1302a-e) has an xy component equal to the corresponding grating vector. That is. For example, the xy components of the ± 1 diffraction order of the incident light beam or the beam of light are G ₁ and G _-1 , respectively. On the other hand, the magnitude of the new k-vector is constrained to 2π / ω, so all new k-vectors (eg, 1302a-e) are on a semicircle, as shown in FIG. 13H. The in-plane component of the incident k-vector 1302 is added to the lattice vector whose length is equal to or twice the basic increment, while the magnitude of each resulting k-vector is Because of the constraints, the angles between the k-vectors (eg, 1302a-e) for different diffraction orders are not equal. Rather, the k-vector (eg, 1302a-e) becomes more angularly sparse as the diffraction order increases.

In the case of diffraction gratings formed on or in a planar eyepiece waveguide, the in-plane components of the new k-vector (eg, 1302a-e) are in the k-spatial ring 1310 of the eyepiece waveguide. The most noticeable is that the diffracted beam or beam of light will undergo guided propagation through the eyepiece waveguide. However, if the in-plane component of the new k-vector (eg, 1302a-e) is in the central disk 1308b, the diffracted or beam of light will exit the eyepiece waveguide.

FIG. 13I illustrates the side view of the grating 1320 and its effect in k-space over the k-vector 1302 corresponding to the obliquely incident light or beam of light. The effect is similar to that described for FIG. 13H. Specifically, the k-vector of a diffracted ray or beam of light is obtained by adding a vector of in-plane components of the incident k-vector with a lattice vector (G _{- 2} , G _{- 1} , G1, G2). It is determined. With respect to the obliquely incident k-vector 1302, the component of the k-vector in the xy plane of the diffraction grating 1320 is non-zero. This component is added to the lattice vector and determines the in-plane component of the new k-vector for the diffracted ray or beam of light. The magnitude of the new k-vector is constrained to 2π / ω. Also, again, when the in-plane component of the k-vector of the diffracted ray or beam of light is within the k-spatial ring 1310 of the eyepiece waveguide, the diffracted ray or beam of light is the eyepiece. It will undergo guided propagation through the waveguide.

FIG. 13J is a k-space schematic illustrating a field of view (FOV) of an image projected into an AR eyepiece waveguide (eg, 1200, 1300). The k-space schematic includes a larger disk 1308a that defines the k-vector of a light beam or ray that can propagate within the eyepiece waveguide. The k-space schematic also includes a smaller disk 1308b that defines the k-vector of a light beam or ray that can propagate within a medium such as air surrounding the eyepiece waveguide. Also, as already discussed, the k-space ring 1310 defines a k-vector of light beam or ray that can undergo guided propagation within the eyepiece waveguide.

Input beams (eg, 1202a, 1204a, 1206a) projected into the entrance pupil of the eyepiece waveguide are shown in FIGS. 12A and 12B. Each input beam has a propagation angle that is uniquely defined by the spatial location of the corresponding image point in the image plane. The set of input beams has angular spreads in both the x- and y- directions. An angular spread in the x-direction can define a horizontal field of view, while an angular spread in the y- direction can define a vertical field of view. In addition, for example, the angular spread of the input beam along the diagonal between the x- and y- directions can define a diagonal field of view.

であって、式中、θ_ｘは、総水平ＦＯＶであって、ｎは、入射媒体の屈折率である。ＦＯＶ矩形１３３０はまた、ｋ_ｙ－軸に沿った寸法を有し、これは、ｙ－方向における入力ビームの角度広がりを定義する。同様に、ＦＯＶ矩形１３３０の垂直高さは、

であって、式中、θ_ｙは、総垂直ＦＯＶである。矩形は、入力ビームのセットを表すように示されるが、いくつかの実施形態では、入力ビームのセットは、ｋ－空間内の異なる形状に対応するであろうようなものであり得る。しかし、概して、ＦＯＶ矩形またはＦＯＶ正方形を使用して示される、本明細書におけるｋ－空間分析は、同様に、ｋ－空間内の他の形状にも等しく適用されることができる。 In k-space, the field of view of the input image can be approximated by the FOV rectangle 1330. The FOV rectangle 1330 surrounds a set of k-vectors corresponding to a set of input light beams. The FOV rectangle 1330 has dimensions along the k _x -axis, which corresponds to the angular spread of the input beam in the x- direction. Specifically, the horizontal width of the FOV rectangle 1330 is

In the equation, θ _x is the total horizontal FOV, and n is the refractive index of the incident medium. The FOV rectangle 1330 also has dimensions along the _y -axis, which defines the angular spread of the input beam in the y-direction. Similarly, the vertical height of the FOV rectangle 1330 is

In the equation, θ _y is the total vertical FOV. The rectangle is shown to represent a set of input beams, but in some embodiments the set of input beams can be such that it would correspond to a different shape in k-space. However, in general, the k-spatial analysis, as shown using FOV rectangles or FOV squares, can be equally applied to other shapes in k-space as well.

As shown in FIG. 13J, the FOV rectangle 1330 is centered on and perfectly located in the smaller disk 1308b. This position of the FOV rectangle 1330 is a set of input beams (eg, on the axis from the image source, i.e., in a configuration with telecentric projections), or generally a set of output beams propagating in the ± z- direction (provided). , The set of beams is centered on the z-axis and all beams have some amount of angular deviation in the ± z- direction, except those that are normal to the entrance or exit pupil). Corresponds to the k-vector of. In other words, the FOV rectangle 1330 represents the input beam as they propagate from the image source through the free space to the eyepiece waveguide when in the smaller disk 1308b in the k-space schematic. be able to. It can also represent the output beam as they propagate from the eyepiece waveguide to the user's eye. Each k-space point in the FOV rectangle 1330 corresponds to a k-vector representing one of the input beam directions or one of the output beam directions. The FOV rectangle 1330 must be translated into the k-space ring 1310 in order for the input beam represented by the FOV rectangle 1330 to undergo guided propagation within the eyepiece waveguide. Conversely, the FOV rectangle 1330 must be antiparallel moved from the k-space ring 1310 to the smaller disk 1308b in order for the output beam represented by the FOV rectangle 1330 to exit the eyepiece waveguide. It doesn't become. The FOV rectangle 1330 of the input beam can match the FOV rectangle of the output beam in order not to introduce geometric and color dispersion from propagation through the waveguide. That is, in this configuration, the eyepiece waveguide stores the beam angle from input to output.

ＦＯＶが、θ_ｘ＝０に水平に中心合わせされる場合、従来の接眼レンズ導波管は、以下の限界を有し得る。

角周波数に関するｍａｘ（ＦＯＶ_ｘ）の唯一の依存性は、角周波数への導波管屈折率の依存性からのものであって、これは、いくつかの用途では、重要な詳細であり得るが、多くの場合、比較的に小さい効果を有する。 The following equation describes the FOV that can be achieved within some eyepiece waveguides.

Conventional eyepiece waveguides may have the following limitations when the FOV is horizontally centered at θ _x = 0.

The only dependence of max (FOV _x ) on angular frequency is from the dependence of the waveguide index on angular frequency, although this can be an important detail in some applications. , Often have a relatively small effect.

FIG. 13K is a k-space schematic showing the translational shift in k-space of the FOV rectangle 1330 caused by the input coupling lattice (ICG) located at the entrance pupil of the eyepiece waveguide. The ICG has an associated grating vector (G _-1 , G ₁ ), as just discussed for FIGS. 13G-13I. The ICG diffracts each of the input beams represented by the FOV rectangle 1330 to a +1 diffraction order and a -1 diffraction order. In k-space, the diffraction of the input beam to the +1 diffraction order is represented by the FOV rectangle 1330 displaced in the _{k x} − direction by the G1 lattice vector. Similarly, in k-space, the diffraction of the input beam to the -1 diffraction order is represented by the FOV rectangle 1330 displaced in the -k _x- direction by the G _-1 lattice vector.

For the particular embodiment shown in FIG. 13K, the translated FOV rectangle is too large to fit entirely within the k-space ring 1310. This is because the eyepiece waveguides support all of the input beams in the FOV in guided propagation mode, regardless of whether they are in positive or negative diffraction order because the angular spread between them is too great. Means that you cannot. The k-vectors corresponding to the points in the translated FOV rectangle outside the larger disk 1308a will not be diffracted by the ICG at all because those k-vectors are not allowed. (This is also ± 2 and higher, in this case because the lattice vector associated with their order will be longer and therefore will translate the k-vector further outward of the larger disk 1308a. On the other hand, if any part of the translated FOV rectangle will still be inside the smaller disk 1308b after translation by the ICG, they will prevent diffraction to the diffraction order. The light beam corresponding to a particular k-vector of is not TIR, so by transmitting through its plane, it will exit the eyepiece lens waveguide and not undergo guided propagation through the waveguide.

One possible modification that can be made to support many of the input beams of light represented by the translated FOV rectangle 1330 in inductive mode is the index of refraction of the eyepiece waveguide and ambient medium. It can be to increase the difference between. This increases the size of the larger disk 1308a and / or decreases the size of the smaller disk 1308b (decreasing the size of the smaller disk 1308b is possible if the waveguide is not surrounded by air. It will increase the size of the k-space ring 1310.
An exemplary AR eyepiece waveguide with an orthogonal pupil expander

FIG. 14A illustrates an exemplary eyepiece waveguide 1400 with an ICG region 1440, an orthogonal pupil expander (OPE) region 1450, and an exit pupil expander (EPE) region 1460. FIG. 14B includes a schematic k-space diagram illustrating the effects of each of these components of the eyepiece waveguide 1400 in k-space. The ICG region 1440, OPE region 1450, and EPE region 1460 of the eyepiece waveguide 1400 include various diffraction features that couple the input beam into the eyepiece waveguide and via an induction mode. It propagates, replicates the beam at multiple dispersal locations in space, and emits the duplicate beam out of the eyepiece waveguide and projects it towards the user's eye.

The input beam corresponding to the input image can be projected from one or more input devices into the eyepiece waveguide 1400. The input beam is incident on the ICG region 1440, which may coincide with the entrance pupil of the eyepiece waveguide 1400. The input device used to project the input beam can include, for example, a spatial light modulator projector (located in front of or behind the eyepiece waveguide 1400 with respect to the user's face). In some embodiments, the input device may use a liquid crystal display (LCD), liquid crystal on silicon (LCOS), fiber scanning display (FSD) technology, or a scanning microelectromechanical system (MEMS) mirror display. But others can also be used. The input beam from the input device is generally projected into the eyepiece waveguide 1400 at various propagation angles in the illustrated −z— direction and from the outside of the substrate of the eyepiece waveguide to the ICG region 1440. Incident on top.

The ICG region 1440 includes a diffraction feature that redirects the input beam so that they propagate inside the eyepiece waveguide 1400 via total internal reflection. In some embodiments, the diffraction feature of the ICG region 1440 consists of many lines extending perpendicular to the y- direction shown and periodically repeating horizontally in the x- direction shown. A one-dimensional period (1D) diffraction grating may be formed. In some embodiments, the lines may be etched into the front or back of the eyepiece waveguide 1400, and / or they may be formed from a material deposited on the front or back. .. The line period, duty cycle, depth, profile, blaze angle, etc. are selected based on the angular frequency ω of the light for which the eyepiece waveguide 1400 is designed, the desired diffraction efficiency of the lattice, and other factors. Can be done. In some embodiments, the ICG region 1440 is primarily designed to couple the input light to +1 and -1 diffraction orders. (The grating can be designed to reduce or eliminate higher diffraction orders above the 0th and 1st order diffraction orders, which is accomplished by properly shaping the profile of each line. However, in many practical ICGs in AR displays, all higher diffraction orders correspond to k-vectors above the k-space ring, thus their higher diffraction order. Regardless of non-k-space attributes such as grating duty cycle, depth, and profile, diffraction beams in one of the ± 1 diffraction orders from the ICG region 1440 will then be generally prohibited. While propagating towards the OPE region 1450 in the −x— direction, the diffraction beam in the other at ± 1 diffraction order then generally propagates in the + x− direction and exits from the eyepiece waveguide 1400.

The OPE region 1450 contains diffraction features capable of performing at least two functions. First, they can generally perform pupil dilation by spatially replicating the input beam of each light in many new locations in the -x- direction. Second, they can guide each replicated beam of light generally on the path towards the EPE region 1460. In some embodiments, these diffraction features are lines formed on or within the substrate of the eyepiece waveguide 1400. The period, duty cycle, depth, profile, line blaze angle, etc. are selected based on the angular frequency ω of the light for which the eyepiece waveguide 1400 is designed, the desired diffraction efficiency of the lattice, and other factors. Can be done. The specific shape of the OPE region 1450 may vary, but is generally determined based on the spread of the beam of light from the ICG region 1440 and the size and location of the EPE region 1460. This is further discussed with respect to FIG. 14D.

The grating in the OPE region 1450 can be designed with relatively low and / or variable diffraction efficiencies. These properties can allow the OPE region 1450 to replicate the beam of light arriving from the ICG region 1440 and / or disperse the light energy in at least one dimension more uniformly. Due to the relatively low diffraction efficiency, each interaction between the beam and the grid diffracts only part of the power in the light beam, while the rest continue to propagate in the same direction. (Some parameters that can be used to affect the diffraction efficiency of the grid are the height and width of the line features or the magnitude of the index of refraction difference between the line features and the background medium.) That is. When the beam interacts with the diffraction grid in the OPE region 1450, some of its power will be diffracted towards the EPE region 1460, while the rest continue to pass through the OPE region and again. , Encountering a grid in different spatial locations, where another portion of the beam's power may be diffracted towards the EPE region 1460, and so on. A portion of the power of each light beam travels further through the OPE region 1450 than the other portion before being diffracted towards the EPE region 1460, thus traveling towards the EPE region from different locations in the -x- direction. There are many copies of the incident beam. The spatial extent of the duplicate beam in the direction of propagation of the original incident beam through the OPE region 1450 is therefore effectively increased, while the intensity of the incident beam is such that the light constituting the input beam is here many duplicate beams. Since it is divided in, it decreases correspondingly.

The grating in the OPE region 1450 is oriented diagonally with respect to the beam arriving from the ICG region 1440 so that the beam is generally diffracted towards the EPE region 1460. The specific angle of the tilt of the grating in the OPE region 1450 may depend on the layout of the various regions of the eyepiece waveguide 1400 and is probably a k-space schematic later found and discussed in FIG. 14B. Can be seen more clearly within. Within the eyepiece waveguide 1400, the ICG region 1440 is located to the right of the OPE region 1450, while the EPE region 1460 is located below the OPE region. Therefore, in order to redirect the light from the ICG region 1440 towards the EPE region 1460, the diffraction grating of the OPE region 1450 may be oriented at about 45 ° with respect to the illustrated x-axis.

FIG. 14C is a three-dimensional illustration of the optical action of the OPE region 1450 shown in FIGS. 14A and 14B. FIG. 14C shows the ICG region 1440 and the OPE region 1450, both on the side of the waveguide closer to the viewer. Lattice lines cannot be seen because they are microscopic. In this case, a single input beam 1401 is shown, but the image will consist of many such input beams propagating in slightly different directions through the eyepiece waveguide 1400. The input beam 1401 is incident on the OPE region 1450 from the ICG region 1440. The input beam 1401 then passes through the total internal reflection of the eyepiece waveguide 1
It continues to propagate through 400, reciprocating between its surfaces and repeatedly reflecting. This is represented in FIG. 14C by a zigzag within the illustrated propagation of each beam.

When the input beam 1401 interacts with a diffraction grating formed within the OPE region 1450, some of its power is diffracted towards the EPE region, while another part of its power is along the same path. , Continue through the OPE region 1450. As already mentioned, this is partly due to the relatively low diffraction efficiency of the grid. Further, the beam diffracted towards the EPE region may re-encounter the grid of the OPE region 1450 and diffract back in the original propagation direction of the input beam 1401. Some paths of these beams are indicated by arrows in FIG. 14C. The effect is replicated as the input beam propagates through the OPE region 1450, thus expanding the spatial extent of the light. This is evident from FIG. 14C, which indicates that the input beam 1401 is replicated to many light beams and eventually travels generally in the −y— direction towards the EPE region. ..

The EPE region 1460 also contains diffraction features capable of performing at least two functions. First, they can replicate the beam along another direction (eg, the direction approximately orthogonal to the direction in which the beam is replicated by the OPE region 1450). Second, they can diffract each beam of light out of the eyepiece waveguide 1400 towards the user's eye. The EPE region 1460 can replicate the light beam in the same way as the OPE region 1450. That is, as the beam propagates through the EPE region 1460, it repeatedly interacts with the grating, diffracting some of its power to the first diffraction order, thereby externally coupling towards the user's eye. Other parts of the beam's power undergo zero-order diffraction and then continue to propagate in the same direction within the EPE region 1460 until they interact with the grid again. The diffractive optical features of the EPE region 1460 are also refracting power to the replicated output beam of light to the extent that they appear as if they originated from the desired depth plane, as discussed elsewhere. Can be granted. This can be accomplished by using the lens function to apply curvature to the grating lines within the EPE region 1460.

FIG. 14B illustrates the action of the eyepiece waveguide 1400 in k-space. Specifically, FIG. 14B includes a k-space schematic (KSD) for each component of the eyepiece waveguide 1400 and illustrates the k-space effect of that component. The FOV rectangle in the k-space schematic and the arrow pointing to the corresponding propagation direction of light through the eyepiece waveguide have matching shadows. The first k-space schematic KSD1 shows a k-space representation of an input beam incident on the ICG region 1440 from an input device. As already discussed, a set of input beams is represented in k-space by a FOV rectangle 1430 whose k _x and _ky dimensions correspond to the angular spread of the input beam in the x- and y- directions. Can be done. Each specific point in the FOV rectangle in KSD1 corresponds to the k-vector associated with one of the input beams, where the k _x component indicates the propagation angle of the input beam in the x- direction and the _ky component. Indicates the propagation angle of the input beam in the y- direction. More precisely, k _x = sin (θ _x ), where θ _x is the angle formed by the input beam and the yz plane, _{ky = sin (θ y )} . In the equation, θ _y is the angle formed by the input beam and the x-z plane. The fact that the FOV rectangle in _KSD1 is centered on the kz-axis of the schematic is the propagation angle at which the represented input light beam is centered around the input beam propagating in the -z- direction. It has, and therefore, means that all input beams generally propagate in the −z— direction. (Although not shown here, any of the waveguide displays described herein can also be designed for FOVs that are off-axis with respect to the ± z-direction.)

The second k-space schematic KSD2 shows the k-space effect of the ICG region 1440. As already discussed, the diffraction grating has an associated grating vector (eg, G ₁ , G _-1 ). KSD2 shows the G ₁ lattice vector and the G _-1 lattice vector, which are equal in magnitude and opposite in the direction along the periodic axis of the ICG. The ICG region 1440 diffracts the input beam to ± 1 diffraction order. Also, in k-space, this means that the ICG copies the FOV rectangle to two new locations by translating it using both the G ₁ and G _-1 lattice vectors. do. In the illustrated instance, the ICG has an angular frequency of the input beam such that the magnitudes of the lattice vectors G ₁ , G _-1 place the copied FOV rectangle completely within the k-space ring of the waveguide. Designed using a period Λ based on ω. Therefore, all diffracted input beams enter guided propagation mode.

A copy of the FOV rectangle centered on a point on the -k _x -axis (9 o'clock position in the k-space ring) has the corresponding diffracted beam and its propagating component in the plane of the eyepiece waveguide 1400. Indicates that the beam has a propagation angle that is centered around the beam in the -x- direction. Therefore, all of these beams propagate generally toward the OPE region 1450, reciprocating and reflecting back and forth between the front and back of the eyepiece waveguide 1400 via the TIR. On the other hand, in a copy of the FOV rectangle centered on a point on the + kx-axis (3 o'clock position in the _k -space ring), the corresponding diffracted beam has its propagating component in the plane of the eyepiece waveguide 1400. Indicates that has a propagation angle centered around the beam in the + x- direction. Therefore, all of these beams propagate back and forth between the front and back of the eyepiece waveguide 1400 via the TIR and generally propagate towards the right edge of the eyepiece waveguide 1400. .. In this particular eyepiece waveguide 1400, those beams are generally lost and do not make a significant contribution to the projection of the image towards the user's eye.

KSD2 does not show a higher-order lattice vector, which is a multiple of the illustrated first-order lattice vectors G ₁ and G _-1 . Because doing so would translate the k-vector, which in this instance constitutes a FOV rectangle beyond the perimeter of the k-space disk that defines the permissible k-vector. Do not diffract the light beam to their diffraction order. Therefore, higher diffraction order does not occur in this embodiment.

The third k-space schematic KSD3 shows the k-space effect of the OPE region 1450. Again, since the OPE region 1450 contains a diffraction grating, it has an associated lattice vector (eg, G ₁ , G _-1 ), which is of equal size and along the periodic axis of the OPE grating. Can be the opposite. In this case, the periodic axis of the diffraction grating is at an angle of 45 ° with respect to the x-axis. Therefore, the lattice vector of the OPE diffraction grating (eg, G ₁ , G _-1 ) points to a 45 ° angle with respect to the k _x -axis. As shown in _KSD3 , one of the lattice vectors translates the FOV rectangle to a new location centered on a point located on the -ky-axis (6 o'clock in the k-space ring). Move it. This copy of the FOV rectangle has a propagation angle at which the corresponding diffracted beam is centered around the beam whose propagation component in the plane of the eyepiece waveguide 1400 is in the −y— direction towards the EPE region 1460. Show that you have. On the other hand, other illustrated OPE lattice vectors will place the FOV rectangle in a location outside the perimeter of the k-space disc. However, the k-vector on the outside of the disk is not acceptable and therefore the OPE grating does not diffract the beam to its diffraction order. The periodic axis of the diffraction grating in the OPE region 1450 does not necessarily have to be exactly 45 °. For example, as can be seen by scrutiny of KSD3, the periodic axis still translates the FOV rectangle to the 6 o'clock position where the FOV rectangle can be totally fitted within the k-space ring, but somewhat 45. Can be greater than or less than °. This will place the FOV rectangle at 6 o'clock, not necessarily centered in the k-space ring along the _-ky -axis.

In the illustrated instance, the OPE grating installs a copied FOV rectangle at 6 o'clock, where one of the lattice vectors G ₁ and G _-1 is completely within the k-space ring of the waveguide. As such, it is designed using a period Λ based on the angular frequency ω of the input beam. Therefore, all diffracted input beams remain in guided propagation mode. The k-space distance from 9 o'clock to 6 o'clock in the k-space ring, which is the translation performed by the OPE lattice, is the translation performed by the ICG, from the origin of the k-space schematic. The OPE lattice vector must be different in magnitude from the ICG lattice vector in order to exceed the distance to. In particular, the OPE grid vector is longer than the ICG grid vector, which means that the OPE grid therefore has a shorter period Λ than the ICG grid.

The fourth k-space schematic KSD4 shows the k-space action of the EPE region 1460. Again, since the EPE region 1460 contains a diffraction grating, it has an associated lattice vector (eg, G ₁ , G _-1 ), which is of equal size and along the periodic axis of the EPE grating. Is the opposite. In this case, the periodic axis of the diffraction grating is along the y-axis of the eyepiece waveguide 1400. Therefore, the lattice vector of the EPE diffraction grating (eg, G ₁ , G _-1 ) points in the ± _ky − direction. As shown in KSD4, one of the lattice vectors translates the FOV rectangle to a new location centered on the origin of the k-space schematic. This copy of the FOV rectangle has a propagation angle at which the corresponding diffracted beam is centered around the beam whose propagation component in the plane of the eyepiece waveguide 1400 is in the + z- direction towards the user's eye. Show that. The other primary EPE grating vector, on the other hand, places the FOV rectangle at a location outside the perimeter of the k-space disc, so the EPE grating does not diffract the beam to its diffraction order. However, one of the quadratic EPE lattice vectors will translate the FOV rectangle to the 12 o'clock location in the k-space ring. Therefore, the EPE grid may diffract part of the light into one of the second diffraction orders. The secondary diffraction direction may correspond to the induced propagation direction along the + y- direction, which is typically an undesired effect. For example, second-order diffraction can result in visual artifacts and flare or blurring effects in the image presented to the user when the EPE grid is perturbed and introduces refractive power, as discussed below. ..

In the illustrated instance, the EPE grating installs one of the lattice vectors G ₁ and G _-1 so that the copied FOV rectangle is completely inside the k-space disk of the waveguide. As such, it is designed using a period Λ based on the angular frequency ω of the input beam. Therefore, all beams diffracted by the EPE grating are no longer in guided propagation mode and therefore exit from the eyepiece waveguide 1400. Further, since the EPE diffraction grating translates the FOV rectangle back to the origin of the k-space schematic (where the FOV rectangle corresponding to the input beam is located), the output beam propagates in the same manner as the corresponding input beam. Has an angle. In the illustrated embodiment, the EPE grating has the same period Λ as the ICG because both of these gratings translate the FOV rectangle by the same k-space distance. However, this is not a requirement. If the _ky dimension of the FOV rectangle is less than the _ky dimension of the k-space ring at 6 o'clock, then the FOV rectangle has a possible range of 6 o'clock positions at different _ky locations within the ring. Can be done. Therefore, there may be numerous engineering options for the EPE lattice vector, and thus the OPE vector, to place the FOV rectangle in place in the k-space ring and / or near the origin of the k-space schematic.

In some embodiments, the lines of the EPE grating may be slightly curved to impart refractive power to the output beam emitted from the EPE region 1460. For example, the lines of the grating in the EPE region 1460 can be bent towards the OPE region in the plane of the waveguide to impart negative power. It can be used, for example, to make the output beam follow the divergence path, as shown in FIG. 12B. This causes the projected image to appear in a depth plane closer to optical infinity. The specific curvature can be determined by the lens function. Within k-space, this means that different spatial regions within the EPE region 1460 will have grid vectors pointing in slightly different directions, depending on the curvature of the grid lines within that specific region. In these embodiments, it translates the FOV rectangle to a variety of different locations centered around the origin of the k-space schematic. This in turn centers the set of output beams corresponding to each of the translated FOV rectangles around different propagation angles, which in turn creates the illusion of depth.

FIG. 14D illustrates techniques for determining the size and shape of OPE regions 1450 and EPE regions 1460. FIG. 14D illustrates the same eyepiece waveguide 1400 as shown in FIGS. 14A and 14B, including an ICG region 1440, an OPE region 1450, and an EPE region 1460. FIG. 14D also includes simplified versions of the k-space schematics KSD1, KSD2, and KSD3. Referring to the first k-space schematic KSD1, the four angle k-vectors of the FOV rectangle correspond to the input beam incident on the ICG at the most bevel angle from the corner of the image in the input plane ( (See FIGS. 12A and 12B). Since the propagation angle of these input beams is the most extreme of all in the field of view, their k-vectors are located at the four corners of the FOV rectangle in k-space.

FIG. 14D shows a ray that defines four diffracted beams from the ICG region 1440 that correspond to the four corners of the input image. In particular, the light rays near the top of the OPE region 1450 correspond to the input beam incident on the ICG region 1440 in the upward direction and at the steepest propagation angle away from the OPE region, the diffracted beam (ie, the upper right corner of the FOV rectangle). Define the k-vector) located in. Also, the light rays near the bottom of the OPE region 1450 are at the diffracted beam (ie, the lower right corner of the FOV rectangle) corresponding to the input beam incident on the ICG region 1450 at the steepest propagation angle downward and away from the OPE region. Define the k-vector) to be located. These two beams define the spread of the diffracted beam from the ICG region 1440. The top and bottom boundaries of the OPE region are the propagation of these two beams to create these two beams and all other replicated instances in between and project them towards the user's eye. The route should be included. The specific propagation path can be determined with reference to the second k-space schematic KSD2.

KSD2 shows the resulting k-vector of the beam diffracting from the ICG region 1440 towards the OPE region 1450. The arrow in KSD2 indicates the propagation angle of the beam corresponding to the k-vector located in the upper right corner of the FOV rectangle.

The size, shape, and location of the EPE region 1460 can be determined by performing a back ray trace using the propagation angle, which is evident from the k-vector in the third k-space schematic KSD3. can. As is evident from the KSD3, the left and upper right angle k-vectors of the FOV rectangle define the spread of the propagation path that the beam follows while propagating in the direction from the OPE region 1450 to the EPE region 1460. Propagation defined by the left and upper right angle k-vectors by using these propagation angles to trace backwards from the portion of the EPE region 1460 located farthest from the OPE region 1450 (ie, the lower angle of the EPE region). It is possible to determine the origin within the OPE region of those rays that will arrive at the lower angle of the EPE region with an angle. These origins of those rays can be used to determine the remaining boundaries of the OPE region 1450. For example, in order to direct the beam from the OPE region 1450 to the lower left angle of the EPE region 1460, the worst case propagation angle is indicated by the upper right angle k-vector of the FOV rectangle. Therefore, the propagation path with that angle can be used to define the left boundary of the OPE region 1450. Similarly, in order to direct the beam from the OPE region 1450 to the lower right angle of the EPE region, in the worst case, the propagation angle is indicated by the upper left angle k-vector of the FOV rectangle. Therefore, the propagation path with that angle can be used to define the right boundary of the OPE region 1450.

As shown in FIG. 14D, in the case of the illustrated eyepiece waveguide 1400, the EPE region 1460 is located in the −x and −y— directions from the ICG region 1440. Also, some of the diffracted beams extend from the ICG region 1440 along their path in the same direction. First, in order to prevent these diffracted beams from incident on the EPE region before propagating through the OPE region 1450, the ICG region 1440 is + y- so that the spread of the diffracted beam does not intersect the EPE region 1460. It may be located sufficiently far from the EPE region in the direction. This results in a large gap between the lower border of the OPE region 1450 and the upper border of the EPE region 1460. In some embodiments, it may be desirable to reduce the size of the eyepiece waveguide by removing or reducing this gap. FIG. 15A illustrates an exemplary embodiment that accomplishes these goals.

FIG. 15A illustrates an exemplary embodiment of a waveguide eyepiece 1500 in which the OPE region 1550 is tilted and its lower border is located parallel to the upper border of the EPE region 1560. do. In fact, the OPE region 1550 and the EPE region 1560 may actually share a boundary line. According to this embodiment, the size of the waveguide eyepiece 1500 is more compact by reducing or eliminating the gap between the OPE region and the EPE region in the guided eyepiece waveguide embodiment shown in FIG. 14A. Can be made.

To adapt to the tilted orientation of the OPE region 1550, the ICG region 1540 is modified so that the spread of the diffracted beam from the ICG region is tilted to match the tilted orientation of the OPE region 1550. Can be For example, the grid lines of the ICG region 1540 can be oriented so that the diffracted beam does not exit the ICG region in the propagation direction having components in the −y − direction. In addition, the ICG region 1540 is located near the shared boundaries of the OPE region 1550 and the EPE region 1560, but none of the parts of the ICG region extend beyond the shared boundaries in the -y- direction. be able to. The action of the ICG region 1540 can be seen in the k-space schematic shown in FIG. 15B.

FIG. 15B includes a k-space schematic illustrating the action of the eyepiece waveguide 1500 shown in FIG. 15A. The first k-space schematic KSD1 shows a FOV rectangle corresponding to an input beam projected from a projector located outside the eyepiece waveguide 1500 towards the ICG region 1540. In the illustrated embodiment, these input beams have a propagation angle centered around the −z— direction. Thus, in k-space, they can be represented by a FOV rectangle centered on the kz-axis at the origin of _KSD1 .

The second k-space schematic KSD2 shows the effect of the ICG region 1540 on the input beam. The ICG region 1540 diffracts the input beams and redirects them towards the OPE region 1550. Within k-space, this corresponds to translating the FOV rectangle using the lattice vector associated with the ICG region 1540. In this embodiment, the grid lines in the ICG region 1540 are oriented with a periodic axis having components in the + y- direction. This means that the lattice vector associated with the _ICG1540 also has a component in the + ky-direction. The magnitude of this component in the + _ky -direction can be ½ or more of the width of the FOV rectangle in the _ky -direction. This means that none of the parts of the FOV rectangle will extend below the horizontal axis of the k-space schematic KSD2 after being translated by the ICG region 1540. This, in turn, means that none of the diffracted beams from the ICG region 1540 have a propagation angle with components in the _−ky − direction. Therefore, neither of the diffracted beams travels downward from the ICG region 1540 towards the EPE region 1560. Also, therefore, none of the diffracted beams will enter the EPE region 1560 prior to passing through the OPE region 1550.

The third k-space schematic KSD3 shows the effect of the OPE region 1550 on the diffracted beam from the ICG region 1540. As shown, the diffraction grating in the OPE region 1550 is k-.
It can be oriented to redirect the beam of light at an angle corresponding to the FOV rectangle translated from the 6 o'clock position in the space ring to a position slightly displaced. For example, the translated FOV rectangle in KSD3 is displaced from the 6 o'clock position in the k-spatial ring by the same angle as the translated FOV rectangle in KSD2 is displaced from the 9 o'clock position. Can be done. In other words, the translated FOV rectangle in KSD3 can be separated by 90 ° from the translated FOV rectangle in KSD2. However, this specific angle separation is not required. That is, the specific location of each FOV rectangle may depend on the layout of the various regions of the eyepiece waveguide with respect to each other.

Since the translated FOV rectangle in KSD3 is centered around a k-vector with a component in the -k _x- direction, the beam of light from the OPE region 1550 is generally a component in the -x- direction. At an angle with, travel towards the EPE region 1560. From FIG. 15A, it can be seen that due to this angle, part of the light beam from the tip portion 1555 of the OPE region 1550 will not intersect the EPE region 1560. Since the tip portion 1555 of the OPE region 1550 can contribute to a relatively small portion of light to the EPE region 1560, the size advantage of eliminating the upper tip 1555 can outweigh any optical disadvantage. In some embodiments, the waveguide eyepiece 1500 can therefore be made even more compact by eliminating the upper tip 1555 of the OPE region 1550.

Finally, the fourth k-space schematic KSD4 shows that the EPE region 1560 has a diffraction grating designed to translate the FOV rectangle back to the origin of the k-space schematic. The starting location of the FOV rectangle in the KSD4 for the eyepiece waveguide embodiment shown in FIG. 15A is slightly different from the starting location of the FOV rectangle in the KSD4 for the eyepiece waveguide embodiment shown in FIG. 14A. Due to the differences, the design of the waveguide within the EPE region 1560 is also somewhat different. For example, the orientation of the grating line of the diffraction grating within the EPE region 1560 is such that the associated grating vector has a component in the + _kx − direction and the OPE region 1550 extends beyond the left edge of the EPE region 1560. It can be tilted so that it is not necessary (see the discussion in FIG. 14D and the location of the upper right angle k-vector in KSD3 in FIG. 14D and the location of the corresponding k-vector in KSD3 in FIG. 15B. Please compare). This results in the FOV rectangle in KSD4 of FIG. 15B being paralleled back to the origin of the k-spatial schematic, which is the beam of light represented by the paralleled FOV rectangle. As already described herein, it means that it is coupled out of the eyepiece waveguide 1500 towards the user's field of view using the same propagation angle as its corresponding input beam (ie, output). The FOV rectangle representing the beam is co-located with the FOV rectangle representing the input beam in the k-space schematic).

FIG. 15C is another k-space schematic illustrating the action of the eyepiece waveguide 1500 shown in FIG. 15A. The k-space schematic in FIG. 15C is a superposition of all the k-space schematics shown in FIG. 15B. Also, the light beam propagating through the OPE region 1550 generally has a propagation angle in the -k _x- direction (as represented by the FOV rectangle located near the 9 o'clock position in the k-space ring) and generally-. It is also illustrated that it is possible to switch back and forth between the propagation angle in the _ky -direction (as represented by the FOV rectangle located near the 6 o'clock position in the k-space ring). This is indicated by a lattice vector with double arrows between the FOV rectangle near the 9 o'clock position and the FOV rectangle near the 6 o'clock position on the k-space ring. 15D-15F illustrate this behavior in more detail.

FIG. 15D is a schematic representation of the first generation of interaction between the input beam of the eyepiece waveguide embodiment shown in FIG. 15A and the OPE region 1550. The OPE region 1550 of the eyepiece waveguide 1500 includes a diffraction grating consisting of parallel grating lines that repeat in the periodic direction. The direction of periodicity determines the direction of the lattice vector associated with the grating. In this instance, the grid vector with double-headed arrows in FIG. 15C illustrates the action of the OPE region 1550 and points along the direction of the periodicity of the grid lines shown in FIGS. 15D-15F.

FIG. 15D shows an input beam incident on the OPE region 1550 from the ICG region 1540. The input beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 9 o'clock position of the k-space ring in FIG. 15C, i.e., the k-vector. As shown, the first generation of interaction between the input beam and the OPE region 1550 results in two diffracted output beams. That is, part of the power of the input beam is simply reflected from the top or bottom surface of the eyepiece waveguide 1500 as output ₁ and continues in the same xy direction as the input beam (ie, 0th order diffraction). ), A portion of the power of the input beam is diffracted downward as output ₂ to the primary (eg, by the _primary lattice vector G1 in the OPE region). The output ₂ beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 6 o'clock position of the k-space ring in FIG. 15C, i.e., the k-vector. After this first generation of interaction, the output ₁ beam and the output ₂ beam have different propagation angles, but they both still propagate within the OPE region 1550 and are therefore shown in FIGS. 15E and 15F. As such, it may have an additional interaction with the OPE region. Although not shown, other input beams incident on the OPE region 1550 with different propagation angles will behave similarly, but with slightly different input and output angles.

FIG. 15E is a schematic representation of the second generation of interaction between the input beam of the eyepiece waveguide embodiment shown in FIG. 15A and the OPE region 1550. The beam associated with the first generation of interaction is shown with a dashed line, while the beam associated with the second generation of interaction is shown with a solid line. As shown in FIG. 15E, the output beams from the first generation of the interaction, i.e., output ₁ and output ₂ , respectively, here interact with an OPE region 1550 similar to that generated in the first generation. Can be affected. That is, part of the power from the output ₁ beam from FIG. 15D simply continues in the same xy direction (ie, 0th order diffraction), while another part of the power of that beam interacts with the lattice. And is redirected downwards (eg, by the _primary lattice vector G1 in the OPE region). Similarly, some of the power from the output ₂ beam from FIG. 15D simply continues downwards towards the EPE region 1560 (ie, 0th order diffraction), while another part of the power of that beam is the lattice. And generally diffracted in the -x- direction (eg, by the negative reciprocal lattice vector G _-1 in the OPE region) and continue to propagate further into the OPE region 1550 in the same direction as the initial input beam.

After the second generation of interaction occurs within the OPE region 1550, there is an interfering node 1556 where two of the resulting beams intersect. The optical paths followed by each of these beams to reach the interfering node 1556 are substantially the same length. Thus, beams emanating from interfering nodes 1556 propagating in the same direction can have the same or similar phases and are therefore subject to constructive or destructive wave interference with each other. This can result in the image artifacts discussed below.

FIG. 15F is a schematic representation of the third generation of interaction between the input beam of the eyepiece waveguide embodiment shown in FIG. 15A and the OPE region 1550. The beams associated with the first and second generation of interactions are shown with dashed lines, while the beams associated with the third generation of interactions are shown with solid lines. As shown in FIG. 15F, each output beam resulting from the second generation of interaction may again suffer an interaction with an OPE region 1550 similar to that generated in the previous generation. Some of the power of those beams continues in the same direction (ie, 0th order diffraction), while other parts of the power of those beams are, in part, generally in the -x- direction, and in part. , Generally redirected in the −y— direction (ie, by the first-order lattice vectors G ₁ and G _-1 in the OPE region). Generally, all beams propagating in the -x- direction are in a state represented by a FOV rectangle located near the 9 o'clock position in the k-space ring of the k-space schematic in FIG. 15C, while generally-. All beams propagating in the y- direction are in a state represented by a FOV rectangle located near the 6 o'clock position. As can be seen from FIG. 15C, for an OPE region 1550 consisting of a 1D periodic diffraction grating, for any given input beam, the light replica beam corresponding to that input beam has only two directions within the OPE region. (However, the two directions will be different for different input beams incident on the OPE region at different propagation angles).

The third generation of interaction with the OPE region results in the creation of additional interferometer nodes 1556 in which beams with the same or similar optical path lengths intersect each other, potentially constructive or destructive wave interference. Bring. Each node 1556 serves as a light source emitted towards the EPE region 1560. For OPE regions consisting of diffraction gratings with 1D periodicity, the layout of these nodes 1556 can form a uniform grating pattern and thus result in image artifacts, as shown in FIG. 15G.

FIG. 15G is a schematic diagram illustrating how a single input beam 1545 from the ICG region 1540 is replicated by the OPE region 1550 and redirected as multiple beams 1565 towards the EPE region 1560. Each of the duplicate beams 1565 shown to propagate towards or within the EPE region 1560 arises from one of the interfering nodes 1556. These interfering nodes have an ordered distribution and serve as an isolated periodic array of sources. Due to the ordered distribution of the interference nodes 1556, the duplicate beams 1565 that illuminate the EPE region are all separated by the same spacing, but the beams may have non-monotonically variable intensities. Also, as a result, the duplicated light beam 1565 from the OPE region 1550 can illuminate the EPE region 1560 with a relatively sparse non-uniform distribution. In some embodiments, it may be advantageous if the replicative light beam, which illuminates the EPE region of the eyepiece waveguide, can be more evenly dispersed. FIG. 16 illustrates such an embodiment.

(Exemplary AR eyepiece waveguide with multi-directional pupil expander)
FIG. 16A illustrates an exemplary eyepiece waveguide 1600 having a multidirectional pupil expander (MPE) region 1650 rather than an OPE region. At the microscopic level, the illustrated embodiment of the eyepiece waveguide 1600 is similar to the eyepiece waveguide 1500 shown in FIG. 15A. The input beam is coupled into the eyepiece waveguide 1600 by the ICG region 1640. The diffracted beam propagates from the ICG region 1640 towards and through the MPE region 1650, which replaces the OPE region. Finally, the MPE region 1650 diffracts the beam of light towards the EPE region 1660, where they are externally coupled towards the user's eye. The ICG region 1640 and the EPE region 1660 may be designed to function in the same manner as the corresponding regions within the eyepiece waveguide 1500 described with respect to FIGS. 15A-15G. However, the MPE region 1650 is distinctly different from the OPE region 1550 in that it diffracts light in more directions. This feature advantageously reduces the periodic uniformity in the distribution of the light beam within the EPE region 1660, which in turn allows the EPE region to be illuminated more uniformly.

The MPE region 1650 consists of diffraction features that exhibit periodicity in multiple directions. The MPE region 1650 may consist of an array of scattering features arranged in a 2D grid pattern. The individual scattering features can be, for example, recesses or protrusions of any shape. The 2D array of scattering features has an associated lattice vector derived from the reciprocal lattice pattern of the 2D lattice pattern. As an embodiment, the MPE region 1650 may be a 2D periodic diffraction grating consisting of a crossed grating with grid lines repeating along two or more distinctly different periodic directions. This can be accomplished by superimposing two 1D grids with different directions of periodicity.

数学的に、ベクトルｕおよびｖは、空間格子模様を定義し、ＧおよびＨは、基本二重、すなわち、レシプロカル格子模様ベクトルに対応する。Ｇは、ｕに直交し、Ｈは、ｖに直交することに留意されたい。しかしながら、ｕは、必ずしも、Ｈと平行ではなく、ｖは、必ずしも、Ｇと平行ではない。 FIG. 16B illustrates a portion of an exemplary 2D periodic lattice that can be used within the MPE region 1650 shown in FIG. 16A, along with its associated lattice vector. The 2D periodic grid 1650 can be a spatial grid pattern of diffraction features whose periodic direction is illustrated by the vectors u and v. Such a 2D periodic lattice is associated with a lattice vector. The two reciprocal lattice vectors G and H corresponding to the directions u and v of periodicity are mathematically defined by:

Mathematically, the vectors u and v define a spatial grid pattern, and G and H correspond to a fundamental double, i.e., a reciprocal grid pattern vector. Note that G is orthogonal to u and H is orthogonal to v. However, u is not necessarily parallel to H and v is not necessarily parallel to G.

As an embodiment, a 2D periodic grid can be designed or formed by superimposing two sets of 1D periodic grid lines, as shown in FIG. 16B (although a 2D periodic grid is an alternative. In addition, for example, it may consist of individual scattering features located at the intersections of the grid lines shown in FIG. 16B). The first set of grid lines 1656 can be repeated along the direction of the reciprocal lattice vector G. The reciprocal lattice vector G can have a magnitude equal to 2π / a, where a is the period of the first set of grid lines 1656. The 2D grid shown in FIG. 16B is also associated with the harmonics of the first reciprocal lattice vector G. These include high-order harmonics such as -G and 2G, -2G. The second set of grid lines 1657 can be repeated along the direction of the reciprocal lattice vector H. The reciprocal lattice vector H can have a magnitude equal to 2π / b, where b is the period of the second set of grid lines 1657. The 2D grid shown in FIG. 16B is also associated with the harmonics of the second reciprocal lattice vector H. These include high-order harmonics such as -H and 2H, -2H.

Any 2D periodic array of diffraction features will correspond to the entire reciprocal lattice pattern and will have an associated lattice vector pointing in the direction determined by the integer linear combination (superimposition) of the basic lattice vectors G and H. .. In the illustrated embodiment, these superpositions result in an additional lattice vector, which is also shown in FIG. 16B. These include, for example, —G, —H, H + G, HG, GH, and − (H + G). Typically, these vectors are described using two indexes such as (± 1,0), (0, ± 1), (± 1, ± 1), (± 2,0). FIG. 16B illustrates only the first-order lattice vector and its superposition associated with the 2D diffraction grating, but higher-order lattice vectors may also be present.

As already discussed elsewhere herein, the k-space effect of a grid on the set of light beams that make up an image corresponds to the image using the grid vector associated with the grid. It is to translate the FOV rectangle. This is shown in FIGS. 16C and 16D with respect to the exemplary 2D MPE grating shown in FIG. 16B.

FIG. 16C is a k-space schematic illustrating the k-space action of the MPE region 1650 of the eyepiece waveguide 1600 shown in FIG. 16A. The k-space schematic includes a shaded FOV rectangle located near the 9 o'clock position of the k-space ring. This is the location of the FOV rectangle after the ICG region 1640 couples the input beam into the eyepiece waveguide 1600 and redirects towards the MPE region 1650. FIG. 16C shows how the 2D grid in the MPE region 1650 translates the FOV rectangle using the grid vector shown in FIG. 16B. Since there are eight lattice vectors (G, H, -G, -H, H + G, HG, GH, and-(H + G)), the MPE region 1650 considers the FOV rectangle as eight possibilities. Attempts to translate to a new k-space location. Of these eight possible k-space locations, six are outside the outer perimeter of the k-space schematic. These are illustrated using an unshaded FOV rectangle. None of the six lattice vectors results in diffraction because the k-vectors outside the boundaries of the k-space schematic are unacceptable. However, there are two lattice vectors (ie-G and-(H + G)) that result in translation of the FOV rectangle to a new position within the boundaries of the k-space schematic. One of these locations is near the 6 o'clock position in the k-space ring and the other is near the 2 o'clock position. Since the k-vectors at these locations are acceptable and result in a guided propagation mode, the FOV rectangle at these locations indicates that they are shaded and the beam of light is diffracted into those two states. Therefore, the power of the beam of light incident on the MPE region 1650 with the propagation angle indicated by the FOV rectangle located near the 9 o'clock position of the k-spatial ring is partially the power of the other two shaded FOVs. It is diffracted into both the states indicated by the rectangles (ie, the FOV rectangle near the 2 o'clock position and the FOV rectangle near the 6 o'clock position).

FIG. 16D is a schematic k-space diagram further illustrating the k-space effect of the MPE region 1650 of the eyepiece waveguide 1600 shown in FIG. 16A. This particular k-space schematic illustrates the effect of the MPE region 1650 on a beam of light in the propagation state illustrated by the FOV rectangle located near the 2 o'clock position of the k-space ring. Again, the 2D grating in the MPE region 1650 attempts to diffract these beams of light to the diffraction order defined by its eight associated grating vectors. As shown, six of the lattice vectors will translate the FOV rectangle to a position outside the boundaries of the k-space schematic. Therefore, their diffraction order does not occur. These positions are illustrated using an unshaded FOV rectangle. However, two of the lattice vectors (ie, H and HG) translate the FOV rectangle to a position within the boundaries of the k-space schematic. These are illustrated by shaded FOV rectangles located near the 9 o'clock position and near the 6 o'clock position on the k-space ring. Therefore, the 2D diffraction grating in the MPE region 1650 partially transfers the power of the beam propagating in the direction indicated by the FOV rectangle located near the 2 o'clock position of the k-space ring to the other two shaded FOV rectangles. Diffract into both the states indicated by (ie, the FOV rectangle near the 9 o'clock position and the FOV rectangle near the 6 o'clock position).

Although not shown, a similar k-space schematic shows the k-space effect of the MPE region 1650 on a beam of light traveling with a propagation angle indicated by a FOV rectangle located near the 6 o'clock position on the k-space ring. It can be derived as shown. The k-space schematic shows two shadows in which the 2D periodic diffraction grating in the MPE region 1650 partially places the power of their beams near the 9 o'clock position and near the 2 o'clock position on the k-space ring. It will show that it diffracts into both of the states indicated by the attached FOV rectangle.

FIG. 16E is a schematic k-space diagram illustrating the k-space action of the eyepiece waveguide 1600 shown in FIG. 16A. As already mentioned, the eyepiece waveguide 1600 can generally receive an input beam of light that propagates in the −z— direction and is incident on the ICG region 1640 of the waveguide 1600 from an outside source. .. The input beams are represented by a FOV rectangle centered on the _kz -axis at the origin of the k-space schematic. The ICG regions 1640 then have a propagation angle such that they are guided and centered around the propagation direction corresponding to the center point of the FOV rectangle located near the 9 o'clock position of the k-space ring. , Diffract the input beam.

The guided beams are incident on the MPE region 1650, where they can have multiple interactions. During each generation of interaction, some of the respective powers of the beam can undergo zero-order diffraction and continue to propagate in the same direction through the MPE region 1650. In the first generation of interactions, for example, this zero-order diffraction corresponds to that portion of the power of those beams that remains in the state indicated by the FOV rectangle located near the 9 o'clock position of the k-space ring. .. Other parts of the beam's power can be diffracted in new directions. Again, in the first generation of interaction, this is centered around the propagation direction corresponding to the center point of the FOV rectangle located near the 2 o'clock position of the k-spatial ring, with a propagation angle of 6. Create a separate diffracted beam with a propagation direction corresponding to the center point of the FOV rectangle located near the time position.

As long as the beams remain within the MPE region 1650, they can undergo additional interactions, each resulting in a portion of the power of the beam that is zero-order diffracted, continuing in the same direction, or diffracted in a new direction. .. This results in a set of spatially dispersed diffracted beams with propagation angles centered around each of the propagation directions indicated by the center points of the FOV rectangle in the k-space ring shown in FIG. 16E. .. This behavior is represented by double-headed arrows between each pair of FOV rectangles in the k-space ring.

As the input beam of any given light propagates within the MPE region 1650, it is split into many diffracted beams that can travel in only three permissible directions, each of which is the k-space schematic in FIG. 16E. It is defined by the corresponding k-vector in the FOV rectangle in the ring, i.e., a point. (This corresponds to an input beam of any light propagating within the MPE region 1650, however, the three permissible directions will vary slightly depending on the propagation angle at which each initial input beam is incident on the MPE region 1650. Also, some of the power of the input beam of any given light will be diffracted in any of the same three propagation directions after any number of interactions with the MPE region 1650, so that the image Information is stored throughout these interactions.

There is an advantage associated with the MPE region 1650, which has three acceptable propagation directions per input beam, as opposed to the two acceptable propagation directions of the OPE region 1550. These advantages are further discussed below, where an increased number of propagation directions within the MPE region 1650 can result in a more complex distribution of interfering nodes within the MPE region 1650, which in turn can result in interference nodes. It should only be said that the uniformity of illumination within the EPE region 1660 can be improved.

It should be understood that FIG. 16E illustrates the k-space action of an exemplary embodiment of the MPE region 1650. In another embodiment, the MPE region 1650 can be designed such that the input beam of each light can be diffracted in more than three directions within the MPE region. For example, in some embodiments, the MPE region 1650 may be designed to allow diffraction of the input beam of each light in four directions, five directions, six directions, seven directions, eight directions and the like. As already discussed, the diffraction features within the MPE region 1650 may be designed to provide a lattice vector that copies the FOV rectangle to a location within the k-space ring corresponding to the selected diffraction direction. can. In addition, the diffraction features within the MPE region 1650 can be designed with periods corresponding to the magnitude of the lattice vector, which means that these copies of the FOV rectangle are entirely within the k-space ring. It yields some results (and other attempted copies of the FOV rectangle are generally outside the outer perimeter of the k-space schematic).

In some embodiments, the angular separation between each of the permissible propagation directions for a given beam of light inside the MPE region 1650 is at least 45 degrees. If the angular separation between any pair of selected directions is less than this quantity, the diffraction features within the MPE region 1650 will provide a lattice vector for making those angular transitions within the k-space ring. Will need to be designed for. Such a lattice vector will be relatively short compared to the size of the k-space ring due to the smaller angular separation. This can make it more likely that the superposition of the basic MPE lattice vectors will produce a copy of the FOV rectangle that is only partially within the k-space ring, which can result in loss of image information. (If not done with caution, as further discussed herein). In addition, if the angular separation between any pair of acceptable propagation directions within the MPE region 1650 is too small, the resulting relatively short lattice vector will also have lattice vector superposition, partially k-. It may be more likely that you will make a copy of the FOV rectangle inside the central disk of the spatial diagram. This is not desirable as it can result in light being externally coupled from the eyepiece waveguide 1600 towards the user's eye from a location outside the designated EPE region 1660.

Various design guidelines can be modeled when determining the acceptable propagation direction within the MPE region 1650. For example, one acceptable propagation direction can be selected to correspond to the direction from the ICG region 1640 to the MPE region 1650. In addition, only one acceptable propagation direction can be selected such that a beam of light propagating in that direction from a location inside the MPE region 1650 will intersect the EPE region 1660. This ensures that the duplicate beam of light incident on the EPE region 1660 corresponds to each input beam with the same propagation angle. In addition, the acceptable propagation direction inside the MPE region 1650 can be selected so that the FOV rectangles do not overlap. Overlapping FOV rectangles can result in a mixture of image information from different image points, resulting in an afterglow image.

FIG. 16F is a schematic representation of the first generation of interaction between the input beam and the MPE region 1650 of the eyepiece waveguide embodiment shown in FIG. 16A. FIG. 16F shows an input beam incident on the MPE region 1650 from the ICG region 1640. The input beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 9 o'clock position of the k-space ring in FIG. 16E, i.e., the k-vector.

The MPE region 1650 can include many features of 1 μm or less. Also, for each interaction with the MPE region, the input approximately 1 mm diameter beam propagates in three different directions in the TIR (same diameter, but with some percentage of the input beam's original power). Will be split into. One direction corresponds to zero-order diffraction and is the original propagation angle in the plane of the waveguide. The other two directions depend on the lattice vectors G and H of the MPE region 1650. As shown, the first generation of interaction between the input beam and the MPE region 1650 results in three beams. That is, part of the power of the input beam is simply reflected from the top or bottom surface of the eyepiece waveguide 1600 as output ₁ and continues in the same xy direction as the input beam (ie, 0th order diffraction). ), Part of the power of the input beam interacts with the 2D lattice in the MPE region 1650 and is diffracted downwards as output ₂ , and part of the power of the input beam interacts with the lattice and upwards as output ₃ . And it is diffracted to the right. The output ₂ beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 6 o'clock position of the k-spatial ring in FIG. 16E, i.e., the k-vector, while the output ₃ beam is shown. It is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 2 o'clock position, that is, the k-vector. After the first generation of this interaction, the output ₁ beam, output ₂ beam, and output ₃ beam have different propagation angles, as shown in Figure 16G-16I, but they all still remain in the MPE region 1650. It propagates within and can therefore have additional interactions with the MPE region. Although not shown, other input beams incident on the MPE region 1650 with different propagation angles will behave similarly, but with slightly different input and output angles.

FIG. 16G is a schematic representation of the second generation of interaction between the input beam and the MPE region 1650 of the eyepiece waveguide embodiment shown in FIG. 16A. The beam associated with the first generation of interaction is shown with a dashed line, while the beam associated with the second generation of interaction is shown with a solid line. As shown in FIG. 16G, the output beam, output ₁ , output ₂ , and output ₃ from the first generation of interaction are each here with an MPE region 1650 similar to that produced in the previous generation. Can be interacted with. That is, while part of the power of the output ₁ beam from FIG. 16F simply continues in the same xy direction, another part of the power of that beam interacts with the grid and is near the 6 o'clock position. It is diffracted in the direction corresponding to the FOV rectangle located, and yet another portion of the power of the beam interacts with the grid and is diffracted in the direction corresponding to the FOV rectangle located near the 2 o'clock position. Similarly, part of the power of the output ₂ beam from FIG. 16F simply continues towards the EPE region 1660, while another part of the power of that beam interacts with the grid and is near the 9 o'clock position. It is diffracted in the direction indicated by the FOV rectangle located at, and yet another portion of the power of the beam interacts with the grid and is diffracted in the direction corresponding to the FOV rectangle located near the 2 o'clock position. Further, while some of the power of the output ₃ beam from FIG. 16F continues in the direction indicated by the FOV rectangle located near the 2 o'clock position, another part of the power of that beam reciprocates with the grid. It acts and is diffracted in the direction indicated by the FOV rectangle located near the 9 o'clock position, yet another portion of the beam's power interacts with the grid and corresponds to the FOV rectangle located near the 6 o'clock position. It is diffracted in the direction of

FIG. 16H is a schematic representation of the third generation of interaction between the input beam and the MPE region 1650 of the eyepiece waveguide embodiment shown in FIG. 16A. The beams associated with the first and second generation of interactions are shown with dashed lines, while the beams associated with the third generation of interactions are shown with solid lines. As shown in FIG. 16H, each output beam resulting from the second generation of interaction may again suffer an interaction with the MPE region 1650 similar to that generated in the previous generation.

FIG. 16I is a schematic representation of the fourth generation of interaction between the input beam and the MPE region 1650 of the eyepiece waveguide embodiment shown in FIG. 16A. The beams associated with the first, second, and third generations of interaction are shown with dashed lines, while the beams associated with the fourth generation of interactions are shown with solid lines. After all these interactions, all the resulting beams are in three directions allowed inside the MPE region 1650 for any given input beam, i.e. near the 9 o'clock position of the k-spatial ring. It propagates in one of the directions corresponding to the FOV rectangle located, the direction corresponding to the FOV rectangle located near the 2 o'clock position, or the direction corresponding to the FOV rectangle located near the 6 o'clock position. There are nodes that can intersect each other while some of these beams propagate through the MPE region 1650, but the location of those nodes is for the OPE region 1550 as illustrated in FIGS. 15D-15G. It has a more complex distribution. Moreover, the beams can reach each of these nodes via different paths and will therefore not necessarily be homeomorphic to each other. Therefore, image artifacts that can result from an ordered distribution of interfering nodes are reduced within the eyepiece waveguide embodiment 1600, which uses the MPE region 1650 instead of the OPE region (eg, 1550). Can be done. This can be seen in FIGS. 16J and 16K.

FIG. 16J is a schematic diagram illustrating various paths through which the beam may eventually follow the EPE region 1660 through the MPE region 1650. There are several pathways that contain only unidirectional changes, while others contain multiple directional changes (although some of the longer and more complex pathways are inevitably more. Will carry less power). Due to the complexity introduced by the presence of different diffraction angles within the MPE region 1650, there are ultimately many different spacings between the beams of light 1665 that illuminate the EPE region 1660. Also, in fact, any possible spacing between the light beams 1665 can be achieved through a sufficient number of interactions within the MPE region 1650. As shown in FIG. 16K, this can result in more uniform illumination of the EPE region 1660.

FIG. 16K illustrates how a single input beam 1645 from ICG region 1640 is replicated by MPE region 1650 and redirected as multiple beams 1665 towards EPE region 1660. Each of these beams 1665 arises from a dense grid of nodes. There may still be gaps between some of these replica beams, but they are generally gaps between replica beams output from the OPE region (eg, 1550 as shown in FIG. 15G). Smaller and less regular. The MPE region 1650 provides a complex exit pupil pattern, which can illuminate the EPE region 1560 more uniformly, as so many paths are present towards the EPE region 1660, all at different locations. can.

FIG. 16L is a control comparison illustrating the performance of an eyepiece waveguide with an OPE region vs. an eyepiece waveguide with an MPE region. On the left is an eyepiece waveguide 1500 containing an OPE region 1550 with a 1D periodic diffraction grating. As already discussed, the OPE region 1550 illuminates the EPE region 1560 with a sparse set of regularly spaced duplicate light beams. Below the eyepiece waveguide 1500 is a simulated output image. This is a simulated output image that will be projected from the EPE region 1560 of the eyepiece waveguide 1500 in response to an input image consisting of pixels all of the same color and brightness.

FIG. 16L shows, to the right, the eyepiece waveguide 1600, which includes an MPE region 1650 with a 2D periodic diffraction grating. As can be seen from the figure, the MPE region 1650 illuminates the EPE region 1660 more uniformly. Below the eyepiece waveguide 1600 is a simulated output image that is the result of the same input image used in the simulation for the left eyepiece waveguide 1500. From the simulated image on the right, it is clear that the eyepiece waveguide 1600 using the MPE region 1650 achieves a smoother and more uniformly distributed output light. In contrast, the image on the left, which is the simulated output of an eyepiece waveguide 1500 with an OPE region 1550, has visible high spatial frequency striations, which is a duplicate illuminating its EPE region 1560. It results from an isolated and ordered set of light beams.

FIG. 16M further illustrates the performance of the eyepiece waveguide with the MPE region vs. the eyepiece waveguide with the OPE region. The ascending graph in FIG. 16M illustrates the performance of the eyepiece waveguide 1500 shown in FIG. 15A. The graph of the horizontal cross section of the image projected from the main eyepiece waveguide showed relatively high spatial frequency variation, which was visible as stripes in the simulated output image shown in FIG. 16L. .. FIG. 16M shows that the eyepiece waveguide 1500 has an eyebox efficiency of 1.2%. In addition, the point spread function associated with the main eyepiece waveguide is shown. The point spread function illustrates an output image obtained from an eyepiece waveguide in response to an input image of a single bright point. This indicates that the eyepiece waveguide 1500 is very sharp as it has only 2.5-5 arc minutes of blur.

One approach for overcoming high spatial frequency variation in the output image from the eyepiece waveguide 1500 is to introduce some dithering into the OPE region 1550. For example, small variations can be introduced into the orientation angle and / or grid period of the OPE region 1550. This is done in an attempt to destroy the ordered nature of the interfering nodes that may be present within the OPE region 1550. The second and third rows in FIG. 16M illustrate the performance of the eyepiece waveguide 1500 with two different types of dithering. High spatial frequency fluctuations are still present, as can be seen from the horizontal cross section of the projected image with respect to these waveguides. Moreover, the point spread function for these dithered embodiments shows, in some cases, a much larger amount of blur, as much as 45 arcs.

The lower part of FIG. 16M illustrates the performance of the eyepiece waveguide 1600 with the MPE region 1650. The cross section of the projected image for this waveguide shows much less high spatial frequency variation. There is still low frequency spatial variation, which can be corrected much more easily than high spatial frequency variation via software. The eyebox efficiency of this eyepiece waveguide is 0.9%, which is slightly lower than the others. This is the fact that the MPE region 1650 redirects a portion of the input light in the general direction corresponding to the FOV rectangle located near the 2 o'clock position in the ring of the k-space schematic shown in FIG. 16E. Can be caused by. Due to the macroscopic layout of the eyepiece waveguide 1600, the light emitted from the MPE region 1650 with this propagation direction never enters the EPE region and is therefore not projected towards the user's eye. Instead, it is lost from the edge of the waveguide 1600. However, the loss of this light results in only a relatively slight reduction in eyebox efficiency. On the other hand, the point spread function for the eyepiece waveguide 1600 shows that it is very clear with a blur of only 2.5-5 arcs.

16A-16M illustrate an eyepiece waveguide 1600 with an MPE region 1650, having three acceptable propagation directions per input beam. However, other embodiments of the MPE region can be designed to allow even more propagation directions per input beam. One such embodiment is illustrated in FIGS. 17A-17G. These figures illustrate the eyepiece waveguide 1700, which in its microscopic design is the same as the eyepiece waveguide 1600. That is, the eyepiece waveguide 1700 includes an ICG region 1740, an MPE region 1750, and an EPE region 1760, all in the same manner as the corresponding regions within the eyepiece waveguide 1600 shown in FIG. 16A. Arranged in. However, the eyepiece waveguide 1700 differs in its microscopic design of the MPE region 1750.

FIG. 17A illustrates a portion of an exemplary 2D lattice that can be used within the MPE region 1750 of the eyepiece waveguide 1700, along with its associated lattice vector. The 2D periodic grid 1750 can be a spatial grid pattern of diffraction features whose periodic directions are u and v. As already discussed, such a 2D periodic lattice is associated with the reciprocal lattice vectors G and H. As an embodiment, the 2D periodic grid 1750 can be designed or formed by superimposing two sets of 1D periodic grid lines (although the 2D periodic grid can be instead, eg, in FIG. 17A. It can consist of individual scattering features located at the intersections of the shown grid lines). The grid lines 1756 of the first set can be repeated along the direction of the reciprocal lattice vector G. The reciprocal lattice vector G can have a magnitude equal to 2π / a, where a is the period of the first set of grid lines 1756. The 2D grid shown in FIG. 17B is also associated with the harmonics of the first reciprocal lattice vector G. These include high-order harmonics such as -G and 2G, -2G. The second set of grid lines 1757 can be repeated along the direction of the reciprocal lattice vector H. The reciprocal lattice vector H can have a magnitude equal to 2π / b, where b is the period of the second set of grid lines 1657. The 2D grid shown in FIG. 17B is also associated with the harmonics of the second reciprocal lattice vector H. These include high-order harmonics such as -H and 2H, -2H. Also, as already discussed, any 2D periodic array diffraction feature will have an associated lattice vector pointing in the direction determined by the integer linear combination (superimposition) of the basic lattice vectors. In this case, these superpositions result in an additional lattice vector. These are, for example, -G, -H, H + G, HG, GH, and-
(H + G) is included. FIG. 17A illustrates only the first-order lattice vector and its superposition associated with the 2D diffraction grating, but higher-order lattice vectors may also be present.

FIG. 17B is a schematic k-space diagram illustrating the k-space action of the MPE region 1750 of the eyepiece waveguide 1700. The k-space schematic includes a shaded FOV rectangle located near the 9 o'clock position of the k-space ring. This is the location of the FOV rectangle after the ICG region 1740 couples the input beams into the eyepiece waveguide 1700 and redirects them towards the MPE region 1750. FIG. 17B shows how the 2D grid in the MPE region 1750 translates the FOV rectangle using the grid vector shown in FIG. 17A. Due to the existence of eight lattice vectors, the MPE region 1750 attempts to translate the FOV rectangle into eight possible new locations in the k-space schematic. Of these eight possible locations, five are outside the outer perimeter of the k-space schematic. These locations are illustrated using an unshaded FOV rectangle. None of these five lattice vectors results in diffraction, as the k-vectors outside the outer perimeter of the k-space schematic are unacceptable. However, there are three lattice vectors (ie-H, -G, and-(H + G)) that result in translation of the FOV rectangle to a new position within the boundaries of the k-space schematic. One of these locations is near the 6 o'clock position in the k-space ring, the other is near the 12 o'clock position, and the last is near the 3 o'clock position. be. Since the k-vectors at these locations are acceptable and result in a guided propagation mode, the FOV rectangle at these locations is shaded to indicate that the beam of light is diffracted into those three states. Therefore, the beam of light incident on the MPE region 1750 with the propagation angle indicated by the FOV rectangle located near the 9 o'clock position of the k-spatial ring is the other three shaded FOV rectangles (ie, the 12 o'clock position). It is diffracted into all of the states indicated by the FOV rectangle near the 3 o'clock position, and the FOV rectangle near the 6 o'clock position.

Although not shown, a similar k-space schematic is a light traveling with a propagation angle indicated by a FOV rectangle located near the 12 o'clock position, near the 3 o'clock position, and near the 6 o'clock position on the k-space ring. Can be derived to illustrate the k-space effect of the MPE region 1750 on the beam of light. Those k-space schematics show that the 2D grating in the MPE region 1750 diffracts their beams into all of the remaining states shown by the shaded FOV rectangle in the ring of the k-space schematic in FIG. 17B. Will.

FIG. 17C is a schematic k-space diagram illustrating the k-space action of the eyepiece waveguide 1700. The eyepiece waveguide 1700 is generally capable of receiving an input beam of light that propagates in the −z— direction and is incident on the ICG region 1740 of the waveguide 1700 from an outside source. These input beams are represented by a FOV rectangle centered on the _kz -axis at the origin of the k-space schematic. The ICG regions 1740 are then guided so that they have a propagation angle centered around the propagation direction that corresponds to the center point of the FOV rectangle located near the 9 o'clock position of the k-space ring. , Diffract the input beam.

Diffracted beams are incident on the MPE region 1750, where they can have multiple interactions. During each generation of interaction, some of the respective powers of the beam continue to propagate in the same direction through the MPE region 1750. In the first generation of interaction, for example, this will correspond to that portion of the power of those beams that remain in the state indicated by the FOV rectangle located near the 9 o'clock position. Other parts of the beam's power can be diffracted in new directions. Again, in the first generation of the interaction, this is the center point of the FOV rectangle located near the 12 o'clock position of the k-spatial ring, the center point of the FOV rectangle located near the 3 o'clock position, and 6 o'clock. Create a separate diffracted beam with a propagation angle centered around the propagation direction that corresponds to the center point of the FOV rectangle located near the position.

After each interaction, the diffracted beam, which still remains within the MPE region 1750, may undergo additional interactions. Each of these additional interactions results in a portion of the beam's power being diffracted to the zeroth order and continuing in the same direction, while a portion of the beam's power is diffracted in the new direction. This results in a set of spatially dispersed diffracted beams with propagation angles centered around each of the propagation directions indicated by the center points of the FOV rectangle in the k-space ring shown in FIG. 17C. .. This is represented by a double-headed arrow between each pair of FOV rectangles in the k-space ring. In other words, the beam of light propagating within the MPE region 1750 goes from any propagating state represented by one of the FOV rectangles in the k-space ring to any other of these propagating states. You can make a transition.

As the input beam of any given light propagates within the MPE region 1750, it is split into many diffracted beams, which can travel in only four possible directions. Each direction is defined by a corresponding k-vector, i.e., a point within the FOV rectangle within the ring of the k-space schematic in FIG. 17C. (This corresponds to an input beam of any light propagating within the MPE region 1750. However, the four possible directions are slightly depending on the propagation angle at which each initial input beam is incident on the MPE region 1750. Also, some of the power of the input beam of any given light will be diffracted in the same four propagation directions after any number of interactions with the MPE region 1750, so that the image Information is stored throughout these interactions. The additional propagation direction allowed within the MPE region 1750 as compared to the MPE region 1650 described with respect to FIGS. 16A-16M may result in further improvements in illumination uniformity within the EPE region 1760. This can be seen in the schematic shown in FIGS. 17D-17G.

FIG. 17D is a schematic representation of the first generation of interaction between the input beam and the MPE region 1750 of the eyepiece waveguide 1700. FIG. 17D shows an input beam incident on the MPE region 1750 from the ICG region 1740. The input beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 9 o'clock position of the k-space ring in FIG. 17C, i.e., the k-vector.

The MPE region 1750 can include many features of 1 μm or less. Also, for each interaction with the MPE region, the approximately 1 mm diameter beam splits into four beams propagating in four different directions in the TIR (same diameter, but with some percentage of the original power of the input beam). Will be done. One direction corresponds to zero-order diffraction and is the original angle in the plane of the waveguide. The other three directions depend on the lattice vectors G and H of the MPE region 1750. As shown, the first generation of interaction between the input beam and the MPE region 1750 results in four beams. That is, part of the power of the input beam is simply reflected from the top or bottom surface of the eyepiece waveguide 1700 as output ₁ and continues in the same xy direction as the input beam (ie, 0th order diffraction). ), Part of the power of the input beam interacts with the lattice and is diffracted downward as output ₂ , and part of the power of the input beam interacts with the lattice and is diffracted upward as output ₃ and the input beam. Part of the power of is diffracted to the right as output ₄ by interacting with the lattice. The output ₂ beam is shown to propagate in the direction corresponding to the center point of the FOV rectangle located near the 6 o'clock position of the k-space ring in FIG. 17C, i.e., the k-vector, while the output ₃ beam is shown. The center point of the FOV rectangle located near the 12 o'clock position, i.e., shown to propagate in the direction corresponding to the k-vector, the output ₄ beam is the center point of the FOV rectangle located near the 3 o'clock position. That is, it is shown to propagate in the direction corresponding to the k-vector. After the first generation of this interaction, the output ₁ beam, output ₂ beam, output ₃ beam, and output ₄ beam have different propagation angles, as shown in FIGS. 17E-17G, but they all still remain. , May propagate within the MPE region 1750 and therefore have additional interactions with the MPE region. Although not shown, other input beams incident on the MPE region 1750 with different propagation angles will behave similarly, but with slightly different input and output angles.

FIG. 17E is a schematic representation of the second generation of interaction between the input beam and the MPE region 1750 of the eyepiece waveguide 1700. The beam associated with the first generation of interaction is shown with a dashed line, while the beam associated with the second generation of interaction is shown with a solid line. As shown in FIG. 17D, the output beams from the first generation of interaction, i.e., output ₁ , output ₂ , output ₃ , and output ₄ , are each similar here to those that occurred in the previous generation. Can interact with the MPE region 1750. That is, while part of the power of the output ₁ beam from FIG. 17D simply continues in the same xy direction, the other part of the power of that beam interacts with the grid and is near the 12 o'clock position. It is diffracted in the direction corresponding to the FOV rectangle located near the 3 o'clock position and near the 6 o'clock position. Similarly, part of the power of the output ₂ beam from FIG. 17D simply continues towards the EPE region 1760, while the other part of the power of that beam interacts with the grid and is near the 9 o'clock position. , Diffracted in the direction indicated by the FOV rectangle located near the 12 o'clock position and near the 3 o'clock position. Further, some of the power of the output ₃ beam from FIG. 17D simply continues in the direction indicated by the FOV rectangle located near the 12 o'clock position, while the other part of the power of that beam reciprocates with the grid. It acts and is diffracted in the direction indicated by the FOV rectangle located near the 3 o'clock position, near the 6 o'clock position, and near the 9 o'clock position. Finally, part of the power of the output ₄ beam from FIG. 17D simply continues in the direction indicated by the FOV rectangle located near the 3 o'clock position, while the other part of the power of that beam is with the grid. It interacts and is diffracted in the direction indicated by the FOV rectangle located near the 6 o'clock position, near the 9 o'clock position, and near the 12 o'clock position.

FIG. 17F is a schematic representation of the third generation of interaction between the input beam and the MPE region 1750 of the eyepiece waveguide embodiment 1700. The beams associated with the first and second generation of interactions are shown with dashed lines, while the beams associated with the third generation of interactions are shown with solid lines. As shown in FIG. 17F, each output beam resulting from the second generation of interaction may again suffer an interaction with the MPE region 1750 similar to that generated in the previous generation.

FIG. 17G is a schematic representation of the fourth generation of interaction between the input beam and the MPE region 1750 of the eyepiece waveguide embodiment 1700. The beams associated with the first, second, and third generations of interaction are shown with dashed lines, while the beams associated with the fourth generation of interactions are shown with solid lines. After all these interactions, the resulting beam is all located near the four permissible propagation directions with the MPE region 1750 for any given input beam, i.e., near the 9 o'clock position on the k-spatial ring. The direction corresponding to the FOV rectangle, the direction corresponding to the FOV rectangle located near the 12 o'clock position, the direction corresponding to the FOV rectangle located near the 3 o'clock position, or the FOV rectangle located near the 6 o'clock position. Propagating in one of the corresponding directions. There are nodes that can intersect each other while some of these beams propagate through the MPE region 1750, but the location of those nodes is for the MPE region 1650 as illustrated in FIGS. 16A-16M. It has an even more complex distribution. Moreover, these nodes are even less likely to cause interference between the two homeomorphic beams. Therefore, the MPE region 1750 may provide even more uniform illumination of the EPE region 1760.

As an overview, the MPE regions described herein are capable of some or all of the following advantages: That is, the MPE region can expand the image pupil in a plurality of directions at once. The MPE region can create a dense aperiodic array of output pupils. The MPE region can reduce the interference effect between optical paths through the waveguide. MPE-based eyepiece waveguides can achieve improved luminance uniformity with reduced high frequency striations and high image sharpness.

(Exemplary AR eyepiece waveguide with multiple distinctly different regions for replicating the input beam)
FIG. 18A illustrates an exemplary eyepiece waveguide 1800 with an ICG region 1840, two orthogonal pupil expander (OPE) regions 1850a, 1850b, and an exit pupil expander (EPE) region 1860. FIG. 18A also includes a schematic k-space diagram illustrating the effects of each of these components of the eyepiece waveguide 1800 in k-space. The ICG region 1840, OPE region 1850a, 1850b, and EPE region 1860 of the eyepiece waveguide 1800 couple the input beam into the eyepiece waveguide 1800, propagate through the induction mode, and are spatially dispersed. Includes various diffraction features that replicate the beam in the manner in which it is made and eject the duplicate beam out of the eyepiece waveguide and project it towards the user's eye. In particular, the eyepiece waveguide 1800 contains a plurality of distinctly different and / or discontinuous regions for replicating the input beam. Replicated beams from these distinctly different regions can be recombined within the common exit pupil region.

The eyepiece waveguide 1800 illustrated in FIG. 18A is similar to the eyepiece waveguide 1400 illustrated in FIG. 14A, but includes two OPE regions 1850a, 1850b instead of one. The ICG region 1440 in the eyepiece waveguide 1400 diffracted the input beam to +1 and -1 diffraction orders, but the beam in one of these diffraction orders propagated away from the OPE region 1450. Recall that in the end it was lost from the eyepiece waveguide. Therefore, some of the light from the input beam was lost. The eyepiece waveguide 1800 shown in FIG. 18A modifies this by including two OPE regions 1850a, 1850b, one on each side of the ICG region 1840. Thus, the eyepiece waveguide 1800 can utilize both the +1 and -1 diffraction orders of the ICG1840.

The operation of the ICG region 1840 is similar to that described for the ICG region 1440 in FIGS. 14A and 14B. The same k-space schematic KSD1 shown in FIG. 14B is also an illustration of a FOV rectangle corresponding to a set of input beams incident on the ICG region 1840 in FIG. 18A. That is, the FOV rectangle is centered on the origin of the k-space schematic before the input beam is incident on the ICG region 1840.

The k-space schematic KSD2 in FIG. 18A illustrates the action of the ICG region 1840 in the k-space. That is, as discussed for the corresponding k-space schematic in FIG. 14B, the ICG region 1840 is a lattice vector that translates the FOV rectangle to the 3 o'clock and 9 o'clock positions in the k-space ring, respectively. Be associated. The translated FOV rectangle located at 3 o'clock represents a diffracted beam propagating towards the right OPE region 1850b, while the translated FOV rectangle located at 9 o'clock points towards the left OPE region 1850a. Represents a diffracted beam that propagates through.

The action of the left OPE region 1850a is also similar to that described for the OPE region 1450 in FIGS. 14A and 14B. The k-space schematic KSD3a illustrates the k-space action of the left OPE region 1850a and shows that its grating moves the FOV rectangle from the 9 o'clock position to the 6 o'clock position in the k-space ring. The FOV rectangle located at 6 o'clock represents a diffracted beam propagating in the −y— direction towards the EPE region 1860.

The operation of the right OPE region 1850b is similar to that of the left OPE region 1850a, but its associated lattice vector is mirrored around a vertical line with respect to that of the left OPE region 1850a. This is due to the fact that the line of the grating in the right OPE region 1850b is mirrored around the perpendicular to that of the grating in the left OPE region 1850a. As a result of the translation of the diffraction grating lines in the right OPE region 1850b, the effect of the grating in the k-space is as shown in the k-space schematic KSD3b, where the FOV rectangle is placed at 3 o'clock in the k-space ring. It will be translated to the 6 o'clock position. The translated FOVs in KSD3a and KSD3b are co-located at 6 o'clock on the k-space ring. Thus, the power of each input beam is split into +1 and -1 diffraction orders by the ICG region 1840, and their distinctly different diffraction orders travel different paths through the eyepiece waveguide 1800, but they Nevertheless, they arrive at the EPE region 1860 with the same propagation angle. This is because the separate diffraction orders of each input beam, which follow different propagation paths through the eyepiece waveguide 1800, eventually exit from the EPE region 1860 with the same angle and are therefore projected. It means to represent the same point in.

Finally, the action of EPE region 1860 is also similar to that described for EPE region 1460 in FIGS. 14A and 14B. The k-space schematic KSD4 illustrates the k-space action of the EPE region 1860, the diffraction grating of which is from the light beam from both the FOV rectangles (OPE regions 1850a, 1850b) located at 6 o'clock in the k-space ring. It is shown that (consisting of) is translated so as to return to the center of the k-space schematic. As already discussed elsewhere, this means that the EPE region 1860 externally couples the beam of light towards the user's eye, generally in the z- direction.

18B and 18C illustrate the top view of the EPE region 1860 of the eyepiece waveguide 1800 shown in FIG. 18A. The EPE region 1860 is supported directly in front of the user's eye 210. As discussed in any of the specification (see FIGS. 12A and 12B), the EPE region 1860 projects a set of duplicate output beams, each set of duplicate output beams into an eyepiece waveguide. It has a propagation angle that corresponds to one of the projected input beams.

FIG. 18B illustrates one of these sets of duplicate output beams. In this particular case, the duplicate output beam 1861 emitted from the EPE region 1860 travels from left to right. In other words, the replication output beam 1861 has a propagation direction with components in the + x- direction. The main propagation angle of the duplicate output beam 1861 results in a tendency for some of them to intersect the user's eye 210 more than others. In particular, the duplicate output beam 1861 emitted from the left portion of the EPE region 1860 tends to intersect the user's eye 210 due to the center position of the eye 210 and the left / right propagation of the light beam. These light beams are illustrated with solid lines. On the other hand, the duplicate output beam 1861 emitted from the right side portion of the EPE region 1860 has a strong tendency to deviate from the eye 210. These light beams are illustrated with dashed lines.

FIG. 18B also includes a k-space schematic KSD5 illustrating the state of the output beam in k-space after the EPE region has translated the FOV rectangle back to the origin of the schematic. The FOV rectangle is illustrated using two halves. Each half represents half of the horizontal field of view of the eyepiece waveguide 1800. The shaded right half of the FOV rectangle 1832 contains a _k -vector with a component in the + kx-direction. These are k-vectors corresponding to the output beam 1861 emitted from the EPE region 1860 with the type of left / right propagation illustrated in FIG. 18B. Only one set of duplicate output beams 1861 is shown to emanate from the EPE region 1860, but the k-vector is within the shaded right hemisphere 1832 of the FOV rectangle, all output beams are similarly. Will exit the EPE region with a left / right propagation direction. Thus, for all of the output beams whose k-vectors are within the shaded right hemisphere 1832 of the FOV rectangle, those beams emanating from the left side of the EPE region 1860 are those output beams emanating from the right side of the EPE region. It can be said that there is a strong tendency to cross the eye 210.

FIG. 18C illustrates another set of replicative light beams 1862 emitted from the EPE region 1860 of the eyepiece waveguide 1800. However, in this case, the duplicate output beam 1862 emitted from the EPE region 1860 travels from right to left. In other words, the replication output beam 1862 has a propagation direction with components in the -x- direction. The main propagation angle of the duplicate output beam 1862 leads to the opposite observation of what is derived from FIG. 18B. That is, with respect to the output beam 1862 propagating to the right / left, the beam emitted from the right portion of the EPE region 1860 (shown using the solid line) tends to intersect the eye 210, while from the left portion of the EPE region. The emitted light beams (shown with dashed lines) are more prone to eye loss.

Referring to the k-space schematic KSD5 included with FIG. 18C, the k-vector is within the shaded left half of the FOV rectangle 1831, the output beam is accompanied by the type of right / left propagation shown in FIG. 18C. Therefore, it is emitted from the EPE region 1860. The k-vectors are within the shaded left half of the FOV rectangle, 1831, all output beams will have different propagation angles, but all of them, the beams emanating from the right side of the EPE region 1860 will be in the EPE region. It shares the property that it will be more likely to intersect the eye 210 than the output beam emitted from the left side of.

The conclusions that can be drawn from FIGS. 18B and 18C are that half of the EPE region 1860 contributes primarily to half of the horizontal field of view, while the EPE region is based on the light beam actually incident on the user's eye 210. The other half primarily contributes to the other half of the horizontal field of view. Based on this observation, the field of view that can be projected by the eyepiece waveguide does not need to project the entire FOV rectangle from all parts of the EPE region 1960, so in at least one dimension, the eyepiece in the induction mode. It can be extended beyond the range of propagation angles supported by the lens. This is illustrated in FIG.

(Exemplary AR eyepiece waveguide with augmented field of view)
FIG. 19 illustrates an embodiment of an eyepiece waveguide 1900 with an extended field of view. The eyepiece waveguide 1900 includes an ICG region 1940, a left OPE region 1950a, a right OPE region 1950b, and an EPE region 1960. At the microscopic level, the eyepiece waveguide 1900 shown in FIG. 19 can be the same as the eyepiece waveguide 1800 shown in FIG. 18A. However, some of the diffraction features within the eyepiece waveguide 1900 can be designed with properties that allow for an increased field of view in at least one dimension. These features can be clearly understood based on the k-space action of the eyepiece waveguide 1900, illustrated by the k-space schematic shown in FIG.

The k-space schematic shown in FIG. 19 has a larger FOV rectangle than that shown in FIG. 18A. This is because the FOV rectangle in the k-space schematic in FIG. 18A is constrained not to have any dimension larger than the width of the k-space ring. This constraint allows those FOV rectangles to fit entirely within the k-spatial ring at any position around the ring, so that all beams represented by the k-vector within the FOV rectangle are eyepieces. It ensured that it could undergo induced propagation within the eyepiece waveguide 1800 while propagating in any direction in the plane of the lens. However, in the exemplary embodiment of FIG. 19, the FOV rectangle has at least one dimension (eg, k _x dimension) that is greater than the width of the k-space ring. In some embodiments, one or more dimensions of the FOV rectangle can be up to 20%, up to 40%, up to 60%, up to 80%, or up to 100% larger than the width of the k-space ring.

For the particular embodiment illustrated in the k-space schematic of FIG. 19, the horizontal dimension of the FOV rectangle is wider than the k-space ring. The horizontal dimension of the FOV rectangle corresponds to the horizontal spread within the propagation angle of the input beam projected into the eyepiece waveguide. Therefore, the eyepiece waveguide 1900 is illustrated so that it can be used in combination with a FOV rectangle with a larger horizontal dimension, which means that the horizontal field of view of the eyepiece waveguide is increased. do. In the case of an eyepiece waveguide with a refractive index of 1.8 (enclosed by air), the eyepiece waveguide 1800 shown in FIG. 18A is generally capable of achieving a FOV of 45 ° × 45 °. On the other hand, the eyepiece waveguide 1900 shown in FIG. 19 is capable of achieving a maximum FOV of 90 ° × 45 °, although some embodiments of the eyepiece waveguide are eyeboxes. Meet the typical design constraints of volume (it may be advantageous to deliver a portion of the FOV to both sides of the eyepiece waveguide to provide a properly sized eyebox) and sparsely spaced outputs. It may be designed for smaller FOVs of about 60 ° × 45 ° to avoid the net door artifacts resulting from the beam. Techniques for expanding the field of view of the eyepiece waveguide 1900 are described in the context of an expanded horizontal field of view, but the same technique is also used to expand the vertical field of view of the eyepiece waveguide 1900. Can be done. Further, in later embodiments, a similar technique is demonstrated to extend both the horizontal and vertical fields of view of the eyepiece waveguide.

By scrutiny of the k-space schematic in FIG. 19, the illustrated FOV rectangles cannot fit entirely within the k-space ring when located at some location around the ring, but they are at other locations. It can still be seen that when located in, it can fit entirely within the ring. For example, if one dimension of the FOV rectangle is greater than the width of the k-space ring, then the FOV rectangle fits entirely within the ring when the FOV rectangle is located at or near the axis of the magnified dimension. I don't get it. A FOV rectangle whose k _x dimension is greater than the width of the k-space ring is the entire FOV rectangle within the ring when the FOV rectangle is located on or near the k _x -axis (ie, at or near the 3 o'clock and 9 o'clock positions). Cannot fit in. Similarly, a FOV rectangle whose _ky dimension is greater than the width of the k-space ring is a ring when the FOV rectangle is located on or near the _ky -axis (ie, at or near the 12 o'clock and 6 o'clock positions). Cannot fit in as a whole. However, such a FOV rectangle may still fit entirely within the k-space ring when located on or near the opposite axis. A FOV rectangle whose k _x dimension is greater than the width of the k-space ring is still in the ring when the FOV rectangle is located on or near the _ky -axis (ie, at or near the 12 o'clock and 6 o'clock positions). Can be totally adapted to. Similarly, a FOV rectangle whose _ky dimension is greater than the width of the _k -space ring remains when the FOV rectangle is located on or near the kx-axis (ie, at or near the 3 o'clock and 9 o'clock positions). , Can fit entirely within the ring. This is because there is an area in the k-space ring for adapting to a FOV rectangle that is larger in the azimuth direction than in the radial direction.

The radial size of the k-space ring corresponds to a range of propagation angles in the normal direction (ie, thickness direction) with respect to the plane of the waveguide, which supports the guided propagation mode. This range of propagation angles is constrained by Snell's law and the requirements that must be met for TIR to occur. In contrast, the spread of the k-vector in the azimuth dimension of the k-space ring corresponds to various propagation angles in the in-plane direction of the planar waveguide. A wider range of beam propagation angles can be supported because the spread of the propagation angle in the plane of the planar waveguide is not limited by the same constraints as in the thickness direction.

Further, it is possible to convert the spread of the propagation angle in the thickness direction of the eyepiece waveguide in the in-plane direction and vice versa. The diffraction grid (or group of other diffraction features) places the FOV rectangle from one position in the k-spatial ring to another so that the set of beams represented by the FOV rectangle then propagates in the new direction. When translated into, it also diffuses a portion of the previously diffused beam in the thickness direction of the planar waveguide in the in-plane direction, and vice versa. This can be seen, for example, when the grating moves the FOV rectangle in parallel from the 9 o'clock position to the 6 o'clock position in the k-space ring. While at 9 o'clock, the beam spread in the _kx direction corresponds to the physical spread in the thickness direction of the waveguide, where the kx direction corresponds to the radial direction of the _k -space ring. .. However, at the 6 o'clock position, the spread of the beam in the _kx direction corresponds to the physical spread in the in-plane direction of the waveguide because the kx direction corresponds to the azimuth of the _k -space ring at that location. do.

Using these observations, the FOV of the eyepiece waveguide divides the FOV rectangle into multiple subparts and uses diffraction features to create multiple subparts of the FOV in a spatially dispersed fashion. Duplicate the beam and use the diffraction features to eyepiece multiple subparts of the FOV so that the beam corresponding to each subpart of the FOV has the correct propagation angle and recreates the original image. It can be increased by reassembling in the ejection pupil of the lens waveguide. For example, diffraction features make each subpart of the FOV rectangle in k-space so that they ultimately have the same relative position as in the original image with respect to the other subparts of the FOV rectangle. It can be used to translate to one or more locations.

In some embodiments, multiple subparts of the FOV can help ease the constraints for reassembling the entire FOV in the exit pupil of the waveguide, ensuring that all of the beam is present. Can be partially overlapped with each other (eg, different pairs of FOV subparts may include part of the same input beam). For example, in some embodiments, the pair of subparts of the input image FOV may overlap at least 10%, no more than 20%, less than 30%, less than 40%, less than 50%, or more.

The k-space schematic in FIG. 19 KSD2 illustrates the k-space effect of the ICG region 1940 on the input beam projected into the eyepiece waveguide 1900. As discussed in any of the specification, the input beam projected into the eyepiece waveguide 1900 can be represented by a FOV rectangle centered on the origin of the k-space schematic KSD2. The ICG region 1940 translates the location of this FOV rectangle in k-space based on its associated lattice vector. In the case of the ICG region 1840 illustrated in FIG. 18A, the ICG region has a magnitude such that its associated lattice vectors G ₁ and G _-1 are equal to the distance from the origin of the k-space schematic to the midpoint of the k-space ring. Was designed to have. This centered the FOV rectangle within the k-space ring. However, the ICG region 1940 illustrated in FIG. 19 can be designed to have a larger lattice vector. Also, as already discussed, the set of input beams projected into the eyepiece waveguide 1900 can have at least one dimension in k-space that is greater than the width of the k-space ring. ..

これは、以下を与える。

（注記：本方程式はまた、例えば、図２０－２２に示され、下記に説明されるもの等、本明細書に説明される他の接眼レンズ導波管実施形態にも適用されることができる。） In some embodiments, the ICG region 1940 is expanded so that its lattice vectors G ₁ and G _-1 are not inside the inner disk of the k-space schematic so that neither part of the enlarged FOV rectangle is inside the inner disk of the k-space schematic. The FOV rectangle can be designed to translate sufficiently away from the origin of the k-space schematic. In the case of a FOV rectangle whose horizontal dimension is twice the width of the k-space ring, the size of the lattice vectors G ₁ and G _-1 of the ICG 1940 is k-space in order to achieve this goal. It will need to be approximately equal to the radius of the outer disk of the schematic. On the other hand, in the case of a FOV rectangle whose horizontal dimension is simply slightly larger than the width of the k-space ring, the size of the lattice vectors G ₁ and G _-1 in the ICG region 1940 is k in order to achieve this goal. -It will be necessary to exceed the distance from the origin of the spatial diagram to the midpoint of the k-space ring. Mathematically, this means:

This gives:

(Note: The equation can also be applied to other eyepiece waveguide embodiments described herein, such as those shown in FIGS. 20-22 and described below. .)

In other words, this technique for expanding the field of view of the eyepiece waveguide 1900 is such that the lattice vectors G ₁ , G _-1 in the ICG region 1940 have a field of view of the k-space ring of a given eyepiece waveguide. It means that it is designed to be longer than the embodiment, constrained in all dimensions by the range of propagation angles that can fit within the radial dimensions of. This is because the ICG region 1940 is conventionally used for light at a given angular frequency ω because the length of the lattice vectors G ₁ , G _-1 is increased by decreasing the lattice period Λ. It has a finer pitch than would be, and means ensuring that all input beams can be diffracted into inductive mode.

Of course, according to the embodiment illustrated in FIG. 19, the larger size and longer lattice vectors G ₁ , G _-1 of the FOV rectangle are a portion of the translated FOV rectangle after diffraction by the ICG region 1940. , K-Extends beyond the perimeter of the larger disk in the spatial schematic. Since the k-vectors outside the disk are not allowed, the input beam corresponding to those k-vectors is not diffracted by the ICG region 1940. Instead, only the input beam corresponding to the k-vector in the shaded portion of the translated FOV rectangle in KSD2 enters the guided propagation mode within the eyepiece waveguide 1900. The input beam, which will diffract to +1 order with the k-vector that will be outside the outer disk of the k-space schematic, is not allowed to diffract and is therefore lost. Similarly, the input beam, which will diffract to -1 degree with the k-vector that will be outside the outer disk of the k-space schematic, is not allowed to diffract and is therefore lost. To. Fortunately, the beams lost from each of these diffraction orders are not the same. This allows the complete field of view to be restored in the EPE region 1960. k-Spherical Diagram A truncated FOV rectangle located at 3 o'clock or a truncated FOV rectangle located at 9 o'clock in KSD2, even if they do not contain a complete set of input beams. When the rectangles are properly recombined in the EPE region 1960, the complete set of input beams can be restored.

k-space Schematic diagrams KSD3a and KSD3b illustrate the k-space action of diffraction gratings in the left OPE region 1950a and the right OPE region 1950b, respectively. As discussed with respect to FIG. 18A, these OPE regions can include diffraction gratings that are oriented to translate the FOV rectangles located at 3 o'clock and 9 o'clock positions to 6 o'clock positions. However, in the embodiment illustrated in FIG. 19, the orientation of the diffraction grating in the OPE regions 1950a, 1950b may need to be adjusted to accomplish this purpose. Specifically, the lattice vectors G ₁ and G _-1 , associated with the ICG region 1940, were associated with the OPE region because they can no longer be terminated at the midpoint of the k-space ring at the 3 o'clock and 9 o'clock positions. The magnitude and orientation of the lattice vector needs to be adjusted to translate the FOV rectangle to a location at 6 o'clock (eg, centered within the k-space ring in the _ky -direction). possible. These adjustments are made by altering the orientation of the grid lines within the OPE regions 1950a, 1950b and / or by altering their grid period Λ compared to the OPE region in embodiments without extended FOV. Can be accomplished.

The shaded right part of the FOV rectangle in KSD3a represents the first subpart of the FOV, while the shaded left part of the FOV rectangle in KSD3b represents the second subpart of the FOV. In the illustrated embodiment, these FOV subparts overlap within the central region of the FOV rectangle.

The k-space schematic KSD3a illustrates that when the FOV rectangle located at 9 o'clock is translated to the 6 o'clock position, only the beam corresponding to the shaded right region of the FOV rectangle is present. The k-space schematic KSD3b shows the same phenomenon, but the absent beam has its k-vector located on the opposite side of the FOV rectangle. Finally, the k-space schematic KSD4 shows that when the two truncated FOV rectangles are superimposed at 6 o'clock on the k-space ring, the unshaded portion of the FOV rectangle is filled, showing that the input image is filled. It means that all the beams constituting the complete FOV are present here and can be projected out of the eyepiece waveguide 1900 towards the user's eye by the diffraction grating in the EPE region 1960. Similar to the embodiment in FIG. 18A, the EPE region 1960 translates the FOV rectangle back to the origin in the k-space schematic KSD4. Importantly, the two truncated FOV rectangles from the 9 o'clock and 3 o'clock positions should be translated to the 6 o'clock position in such a way as to maintain the relative position of the shaded area within the original FOV rectangle. Is. This ensures that the beam of light within each sub-part of the FOV has the correct propagation angle to recreate the original image.

What this means from a physical point of view is that the eyepiece waveguide 1900 divides the image field of view into a plurality of parts. The light beams corresponding to each of these parts of the image field propagate along different paths through the eyepiece waveguide 1900, where they, in a spatially dispersed manner, differ from the OPE region 1950a. Can be duplicated by 1950b. Also, finally, the separate parts of the image field of view are recombined within the EPE region 1960 and projected towards the user's eye.

In some embodiments, the various diffraction gratings of the eyepiece 1900 can be designed so that there is overlap between the subsets of beams supplied to the EPE region 1960 by the individual OPE regions 1950a, 1950b. .. In other embodiments, however, the grating may be designed such that each OPE region 1950a, 1950b provides a unique subset of beams required to completely recreate the input image. can. An exemplary AR eyepiece waveguide with augmented field of view and overlapping MPE and EPE regions

FIG. 19 illustrates an embodiment of an eyepiece waveguide with an extended FOV that replicates the input beam using the OPE region, while other embodiments advantageously use the MPE region. be able to. 20A-20L illustrate one such exemplary embodiment.

FIG. 20A illustrates an embodiment of an extended FOV eyepiece waveguide 2000 with an MPE region 2050 overlapped by an EPE region 2060. The eyepiece waveguide 2000 can achieve an extended field of view that can be larger than the range of propagation angles that can be supported by the guided propagation mode in the thickness direction of the waveguide. The eyepiece waveguide 2000 has a first surface 2000a and a second surface 2000b. Further, as discussed below, different diffraction features can be formed on or within the opposite surfaces 2000a, 2000b of the eyepiece waveguide 2000. The two surfaces 2000a, 2000b of the eyepiece waveguide 2000 are shown in FIG. 20A so as to be displaced relative to each other in the xy plane. However, this is for illustration purposes only and it is possible to show different diffraction features formed on or within each surface. It should be understood that the first surface 2000a and the second surface 2000b are aligned with each other in the xy plane. In addition, MPE regions 2050 and EPE regions 2060 are shown to be exactly the same size and exactly aligned in the xy plane, but in other embodiments they have somewhat different sizes. It may be partially inconsistent. In some embodiments, the MPE region 2050 and the EPE region 2060 overlap each other by at least 70%, at least 80%, at least 90%, or at least 95%.

The eyepiece waveguide 2000 includes an ICG region 2040, an MPE region 2050, and an EPE region 2060. The ICG region 2040 receives a set of input beams from the projector device. As described in any of the specification, the input beams can propagate generally in the z- direction from the projector device through free space until they are incident on the ICG region 2040. The ICG region 2040 diffracts their input beams such that all or at least some of them enter guided propagation mode within the eyepiece waveguide 2000. The grid lines of the ICG region 2040 can be oriented so that the diffracted beam is directed towards the MPE region 2050 in the −y— direction.

The MPE region 2050 can include a plurality of diffraction features that exhibit periodicity along the plurality of axes. The MPE region 2050 may consist of an array of scattering features arranged in a 2D grid pattern. The individual scattering features can be, for example, recesses or protrusions of any shape. The 2D array of scattering features has an associated lattice vector derived from the reciprocal lattice pattern of the 2D lattice pattern. As an embodiment, the MPE region 2050 can be a 2D diffraction grating consisting of a crossed grating with grid lines that repeat along two or more directions of periodicity. Diffraction features that make up the MPE region 2050 can have relatively low diffraction efficiencies (eg, 10% or less). As discussed herein, this allows beams of light to be replicated in multiple directions in a spatially dispersed fashion as they propagate through the MPE region 2050.

FIG. 20B illustrates a portion of an exemplary 2D lattice that can be used within the MPE region 2050 of the eyepiece waveguide 2000, along with its associated lattice vector. Crossed grids are shown, but 2D periodic grids may instead consist of individual scattering features located, for example, at the intersections of the shown grid lines. The 2D grid has a first set of grid lines 2056 that repeats along the direction of the first periodicity. These grid lines 2056 point along the direction of the periodicity of the first set of grid lines 2056 and are equal to 2π / a (where a is the period of the first set of grid lines 2056). It has an associated reciprocal lattice vector G with magnitude. The 2D grid shown in FIG. 20B is also associated with the harmonics of the first reciprocal lattice vector G. These include high-order harmonics such as -G and 2G, -2G. The 2D grid within the MPE region 2050 also has a second set of grid lines 2057 that repeats along the direction of the second periodicity. In some embodiments, the directions of the first and second periodicity are not vertical. The second set of grid lines 2057 points along the direction of the periodicity of the second set of grid lines, 2π / b (in the equation, b is the period of the second set of grid lines 2057). Has an associated reciprocal lattice vector H with a magnitude equal to. The 2D grid shown in FIG. 20B is also associated with the harmonics of the second reciprocal lattice vector H. These include high-order harmonics such as -H and 2H, -2H. Finally, any 2D array of diffraction features will also have an associated lattice vector pointing in the direction determined by the integer linear combination (superimposition) of the reciprocal lattice vectors G and H. In the illustrated embodiment, these superpositions result in an additional lattice vector, which is also shown in FIG. 20B. These include, for example, —G, —H, H + G, HG, GH, and − (H + G). FIG. 20B illustrates only the first-order lattice vector and its superposition associated with the 2D diffraction grating, but higher-order lattice vectors may also be present.

FIG. 20C is a schematic k-space diagram KSD1 illustrating the k-space action of the ICG region 2040 of the eyepiece waveguide 2000. The FOV rectangle centered on the origin of KSD1 represents a set of input beams projected by the projector device towards the ICG region 2040. The dimensions of the FOV rectangle in the k _x − direction represent the FOV of the input beam in the x − direction, while the dimensions of the FOV rectangle in the ky − direction represent the FOV of the input beam in the _y − direction. As illustrated, in this particular embodiment, the k _x dimension of the FOV rectangle is greater than the width of the k-space ring.

Since the MPE region 2050 is located in the −y— direction from the ICG region 2040 according to the physical layout of the eyepiece waveguide 2000 shown in FIG. 20A, the diffraction grating in the ICG region 2040 directs the input beam in that direction. It can be designed to diffract. Therefore, KSD1 in FIG. 20C indicates that the ICG region 2040 translates the FOV rectangle from the origin of the k-space schematic to a location on the _-ky -axis at 6 o'clock in the k-space ring. At this particular location, the wider dimensions of the FOV rectangle are oriented in the azimuth direction of the k-space ring, thus the FOV rectangle fits entirely within the ring. This means that all the beams represented by the FOV rectangle enter guided propagation mode within the eyepiece waveguide 2000 and propagate generally towards the MPE region 2050 in the −y— direction.

As in other MPE regions discussed herein (eg, 1650, 1750), the MPE region 2050 replicates the input beam in a spatially dispersed manner as they propagate through it. Expands the image pupil in multiple directions. 20D-20F and 20H illustrate this behavior of the MPE region 2050 in k-space.

FIG. 20D is a schematic k-space diagram KSD2 illustrating a portion of the k-space effect of the MPE region 2050 of the eyepiece waveguide 2000. The k-space schematic includes a shaded FOV rectangle located at 6 o'clock on the k-space ring. This is the location of the FOV rectangle after the ICG region 2040 couples the input beams into the eyepiece waveguide 2000 and diffracts them towards the MPE region 2050. FIG. 20D shows how the 2D grid in the MPE region 2050 translates the FOV rectangle using the grid vector shown in FIG. 20B. Due to the existence of eight lattice vectors, the MPE region 2050 attempts to translate the FOV rectangle from the 6 o'clock position in the k-space ring to eight possible new locations in the k-space schematic. Of these eight possible locations, five are entirely outside the outer perimeter of the k-space schematic. These locations are illustrated using an unshaded FOV rectangle. None of these five lattice vectors results in diffraction, as the k-vectors outside the outer perimeter of the k-space schematic are unacceptable. However, there are three lattice vectors (ie, G, —H, and GH) that result in translation of the FOV rectangle to new positions within the boundaries of the k-space schematic, at least in part. One of these locations is at 9 o'clock in the k-space ring, the other is at 12 o'clock and the last is at 3 o'clock. Since the k-vectors at these locations are acceptable and result in a guided propagation mode, the FOV rectangle at these locations is shaded to indicate that the beam of light is diffracted into those three states.

For 9 o'clock and 3 o'clock positions in the k-space ring, the translated FOV rectangle does not fit perfectly in the ring because its k _x dimension is larger than the width of the ring. Thus, the translated FOV rectangles at these locations mean that the beam is not guided, it is truncated and its k-vector is outside the outer perimeter of the k-space schematic. This is represented in KSD2 by the unshaded portion of the translated FOV rectangle at the 9 o'clock and 3 o'clock positions. This means that each set of beams diffused through the MPE region 2050 in the + x and -x directions does not contain all of the original set of input beams, respectively. A set of beams propagating through the MPE region 2050 in the + x direction misses the beam corresponding to the right side of the FOV rectangle, while a set of beams propagating in the −x direction corresponds to the left side of the FOV rectangle. Have been lost. However, all the beams that collectively make up the FOV are still present.

The shaded right part of the translated FOV rectangle at 9 o'clock represents the first subpart of the FOV, while the shaded left part of the FOV rectangle at 3 o'clock represents the second subpart of the FOV. .. In the illustrated embodiment, these FOV subparts overlap in the central region of the FOV rectangle (although overlap is not always required).

As already mentioned, in some embodiments, the first and second periodic axes within the 2D grid of MPE region 2050 are not orthogonal. This, in turn, means that the reciprocal lattice vectors G and H are also not orthogonal. This is because the 2D grid in the MPE region 2050 has FOV rectangles at 3 o'clock and 9 o'clock, while the center of those rectangles crosses the midpoint of the k-spatial ring, while the FOV at 6 o'clock and 12 o'clock. It can be possible to translate the center of the rectangle so that it can be located at or near the midpoint of the ring. As a result, the translated FOV rectangles at the 3 o'clock and 9 o'clock positions are truncated, which results in the FOV being divided into first and second subparts. It is noteworthy in the illustrated embodiments, as this is part of the process for increasing the FOV of the eyepiece waveguide 2000 by dividing the FOV into first and second subparts. ..

FIG. 20E is a k-space schematic KSD3 illustrating another portion of the k-space effect of the MPE region 2050 of the eyepiece waveguide 2000. KSD3 includes a partially shaded FOV rectangle located at 3 o'clock on the k-space ring. This is the location of one of the translated FOV rectangles within the MPE region 2050 after the first interaction. FIG. 20E shows how the 2D grid in the MPE region 2050 translates the FOV rectangle using the grid vector shown in FIG. 20B during subsequent interactions. Again, because of the existence of eight lattice vectors, the MPE region 2050 translates the FOV rectangle from the 3 o'clock position in the k-space ring to eight possible new locations in the k-space schematic. Try. Of these eight possible locations, five are again outside the outer perimeter of the k-space schematic. These locations are illustrated using an unshaded FOV rectangle. None of these five lattice vectors results in diffraction, as the k-vectors outside the outer perimeter of the k-space schematic are unacceptable. However, there are three lattice vectors (ie, G, H, and H + G) that result in translation of the FOV rectangle to new positions within the boundaries of the k-space schematic, at least in part. One of these locations is at 9 o'clock in the k-space ring, the other is at 12 o'clock, and the last is back at 6 o'clock. Since the k-vectors at these locations are acceptable and result in a guided propagation mode, the FOV rectangle at these locations is shaded to indicate that the beam of light is diffracted into those three states ( Alternatively, the zero-order diffracted beam can remain in the propagating state represented by the FOV rectangle at the 3 o'clock position).

As shown in FIG. 20E, the translated FOV rectangle at the 3 o'clock position of the k-space ring has already been truncated as a result of the first diffraction interaction within the MPE region 2050 shown in FIG. 20D. .. Therefore, only the truncated FOV rectangle is translated into the 9 o'clock, 12 o'clock, and 6 o'clock positions of the k-space ring. For the 9 o'clock position, the FOV rectangle is further truncated, meaning that only the beam corresponding to the centrally shaded portion of that particular translated FOV rectangle is actually diffracted into this state. ..

FIG. 20F is similar to FIG. 20E, but spans the FOV rectangle from FIG. 20D translated to the 9 o'clock position (instead of the 3 o'clock position as illustrated in FIG. 20E) of the MPE region 2050. Shows k-spatial action. The effect of the MPE region 2050 on the beam in this state is a mirror image of what is shown in FIG. 20E (centered on the _ky -axis).

Although not shown, a similar k-space schematic is applied to the beam of light traveling with the propagation angle indicated by the FOV rectangle located at 12 o'clock in the k-space ring, MPE region 2050.
The k-space action of can be derived as illustrated. The k-space schematic shows that the 2D grating in the MPE region 2050 directs their beams to the FOV at 3 o'clock, 6 o'clock, and 9 o'clock positions in the ring of the k-space schematic at FIGS. 20D, 20E, and 20F. It will indicate that it will diffract to the state represented by the rectangle.

As shown by the k-space schematic in FIGS. 20D-20F, when the diffracted light beam from the ICG region 2040 arrives at the MPE region 2050, many replica beams are formed in a spatially dispersed fashion. Also, all of these duplicate beams propagate in one of the directions indicated by the FOV rectangle at the 3 o'clock, 6 o'clock, 9 o'clock, and 12 o'clock positions in the k-space ring. The light beam propagating through the MPE region 2050 is subject to any number of interactions with the diffraction features of the MPE region and can result in any number of propagation direction changes. Thus, the light beam is replicated along both the x- and y- directions throughout the MPE region 2050. This is represented by the arrows in the MPE region 2050 of the eyepiece waveguide 2000 in FIG. 20A.

Since the EPE region 2060 overlaps the MPE region 2050 in the xy plane of the eyepiece waveguide 2000, the duplicated light beams also have their first diffused through the waveguide and through total internal reflection. As it reciprocates and reflects between the surface 2000a and the second surface 2000b, it interacts with the EPE region 2060. When one of the light beams interacts with the EPE region 2060, a portion of its power is diffracted and the eyepiece lens, as indicated by the arrow in the EPE region 2060 of the eyepiece waveguide 2000 in FIG. 20A. It emits light from the waveguide toward the user's eye.

In some embodiments, the EPE region 2060 comprises a diffraction grating whose lines are oriented perpendicular to the lines of the diffraction grating that make up the ICG region 2040. An example of which is shown in FIG. 20A, where the ICG region 2040 extends in the x- direction and has a grid line that is periodically repeated in the y-direction, while the EPE region 2060 extends in the y- direction. It has grid lines that are present and periodically repeat in the x-direction. The grid lines within the EPE region 2060 help ensure that the light beam will interact with the MPE region 2050 before being coupled out of the eyepiece waveguide 2000 by the EPE region 2060. Therefore, it is advantageous to be oriented perpendicular to the grid lines in the ICG region 2040. This behavior is shown in k-space in FIG. 20G.

FIG. 20G is a k-space schematic KSD5 illustrating the k-space action of the EPE region 2060 in the eyepiece waveguide 2000 shown in FIG. 20A. As already discussed, the beam of light propagates through the MPE region 2050 in all directions indicated by the FOV rectangles located at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on the k-space ring. Also, since the EPE region 2060 physically overlaps the MPE region 2050, the beam of light in all of these propagation states is in contact with the diffraction grating in the EPE region while diffusing through the MPE region.

Since the periodic axis of the diffraction grating in the EPE region 2060 points in the ± k _x − direction, the lattice vector associated with the EPE region also points in the same direction. FIG. 20G shows how the EPE region 2060 attempts to translate the FOV rectangle to the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions using these grid vectors. Due to its orientation in the ± kx-direction, the lattice vector associated with the EPE region 2060 returns only the FOV rectangles located at the 3 o'clock and 6 o'clock positions of the _k -space ring to the origin of the k-space schematic. Can be translated like this. Thus, the EPE region 2060 can only externally couple a beam of light in either of those two propagating states. That is, the EPE region does not externally couple the beam of light propagating in the state corresponding to the FOV rectangle at the 12 o'clock and 6 o'clock positions of the k-space ring.

If the periodic axis for the grid lines in the EPE region 2060 is not perpendicular to the periodic axis for the grid lines in the ICG region 2040, but parallel, then the grid vector associated with the EPE region is ± k. It is important to note that it will point in the _y -direction. This, in turn, will allow the light beam in the propagating state corresponding to the FOV rectangle at the 12 o'clock and 6 o'clock positions of the k-space ring to be externally coupled by the EPE region. The input beam arrives at the MPE / EPE region in the propagating state corresponding to the 6 o'clock position, which is due to the EPE region 2060 before the light beam interacts with and is diffused by the MPE region 2050. It can be outer-coupled, which would typically mean that it would not be desirable. The fact that the periodic axis for the grid lines in the EPE region 2060 is perpendicular to that of the ICG region 2040 is that the light beam is typically at least in the MPE region before it is externally coupled. Once, it means that it will possibly need to exceed it and undergo a change of direction. This allows for an improved spread of the beam of light within the MPE region 2050.

FIG. 20H is a k-space schematic KSD6 summarizing the k-space effect of the eyepiece waveguide 2000 shown in FIG. 20A. This is essentially a superposition of the k-space schematic shown in FIGS. 20C-20G. Again, the k-space schematic in FIG. 20H shows a FOV rectangle having at least one dimension larger than the width of the k-space ring. In some embodiments, at least one dimension of the FOV rectangle can be up to about twice as large as the width of the k-space ring. In the illustrated embodiment, the horizontal dimension of the FOV rectangle is greater than the width of the k-space ring, but the same technique can also be used to extend the vertical field of view.

The KSD 6 includes a FOV rectangle centered on the origin of the schematic. Again, this location of the FOV rectangle either projects the input beam into the eyepiece waveguide 2000 or the duplicate output beam out of the waveguide towards the user's eye. Can be explained. In the illustrated embodiment, the action of the ICG region 2040 in k-space is to translate the FOV rectangle downward from the center of the k-space schematic to the 6 o'clock position. As shown, the ICG region 2040 can be designed such that one of its lattice vectors is oriented in the _−ky − direction. This propagates the diffracted beam in the −y— direction towards the MPE region 2050. In addition, the ICG region 2040 can be designed so that the magnitude of its lattice vector copies the FOV rectangle to a position that does not fit perfectly within the k-space ring at 6 o'clock. This can be done, for example, by designing the ICG region 2040 with a pitch such that the magnitude of its linear lattice vector is equal to the distance from the origin of the k-space schematic to the midpoint of the k-space ring. can. Since the FOV rectangle at 6 o'clock is completely within the k-space ring, all diffracted beams enter the propagation induction mode.

As already discussed, the MPE region contains multiple diffraction features that exhibit periodicity along multiple different axes. This means that the MPE region has multiple associated lattice vectors that can translate the FOV rectangle from the 6 o'clock position to any of the 9 o'clock, 12 o'clock, and 3 o'clock positions. During the additional interaction with the MPE region 2050, the FOV rectangle can be translated back and forth between any of the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions. This is represented by a double-headed arrow between those propagation states. As shown in FIG. 20H, the FOV squares at the 3 and 6 o'clock positions of the k-space ring are truncated and all beams of light associated with the full FOV are present in each of their propagation states. It means that it is not. However, when those subparts of the FOV are collectively examined, all the beams of light that make up the complete FOV are present. Therefore, when the FOV rectangle is finally translated from the 3 o'clock or 6 o'clock position back to the origin of the k-spatial diagram so that the beam of light is externally coupled towards the user's eye, the input. All the beams required to construct a complete FOV of the image are present and projected from the eyepiece waveguide 2000.

FIG. 20I is a schematic diagram illustrating how a beam of light diffuses through the eyepiece waveguide 2000 shown in FIG. 20A. The guided beam incident on the MPE region 2050 and propagating from the ICG region 2040 in the -y- direction is replicated to many beams in a spatially dispersed fashion, some in the ± y- direction (k-). Proceed in the ± x- direction (corresponding to the FOV rectangle at 3 o'clock and 9 o'clock in the k-space ring), partly in the ± x- direction (corresponding to the FOV rectangle at 6 o'clock and 12 o'clock in the space ring). proceed. In this way, the light beam diffuses laterally through the entire eyepiece waveguide 2000.

FIG. 20J illustrates how the diffraction efficiency of the MPE region 2050 in the eyepiece waveguide 2000 can be spatially varied so as to improve the uniformity of brightness in the waveguide. In the figure, darker shadows within the MPE region 2050 represent higher diffraction efficiency, while brighter shadows represent lower diffraction efficiency. Spatial variation in diffraction efficiency of the MPE region 2050 can be accomplished by introducing spatial variation in grid characteristics such as grid depth, duty cycle, blaze angle, tilt angle and the like.

As can be seen in FIG. 20J, the uniformity of luminance in the waveguide can be improved by designing the portion of the MPE region 2050, which is closer to the ICG region 2040, to have higher diffraction efficiency. Since this is the location where the light beam is incident from the ICG region 2040 to the MPE region 2050, more light is present in this area, and therefore the diffraction efficiency is such that the light is less present in the MPE region 2050. It can be higher so that it diffuses more effectively in other parts. In addition, or as an alternative, various ICG regions around the perimeter of the MPE region 2050 so that multiple ICG regions input light to more locations, thereby improving brightness uniformity within the waveguide. Can be provided at an angle location.

Luminance uniformity is also improved by designing the central portion of the MPE region 2050 to have higher diffraction efficiency along the direction in which the beam propagates from the ICG region 2040 into the MPE region 2050. be able to. Again, more light is present within this area of the MPE region 2050 because the ICG region 2040 is located along the axis that inputs the light. Diffraction efficiency can be higher so that the light is more effectively diffused to the rest of the MPE region 2050 as more light is present in this area.

FIG. 20K illustrates how the diffraction efficiency of the EPE region 2060 in the eyepiece waveguide 2000 can be spatially varied so as to improve the uniformity of luminance in the waveguide. Darker shadows within the EPE region 2060 again represent higher diffraction efficiency, while brighter shadows represent lower diffraction efficiency. The EPE region 2060 can be designed to have higher diffraction efficiency in the surrounding area. The higher diffraction efficiency within the peripheral area of the EPE region 2060 helps to externally couple the light to the user's eye before it is lost out of the rim of the waveguide.

FIG. 20L illustrates an embodiment of an eyepiece waveguide 2000 that includes one or more diffraction mirrors 2070 around the peripheral edge of the waveguide. The diffractive mirror 2070 can receive light that propagates through the MPE / EPE region and exits from the edge of the waveguide 2000. The diffractive mirror can then diffract the light back into the MPE / EPE region so that it can be used to contribute to the projection of the image from the eyepiece waveguide 2000. As already discussed, the MPE region 2050 is generally -x, as represented by the four general directions, that is, generally the x-direction (ie, the FOV rectangle at the 3 o'clock position of the k-space ring). -Direction (ie, as represented by the FOV rectangle at 9 o'clock), generally y-direction (ie, as represented by the FOV rectangle at 12 o'clock)
, And generally allow the beam to propagate in the −y— direction (ie, as represented by the FOV rectangle at 6 o'clock). The diffraction mirror 2070 can be designed to diffract the beam into one of these identical propagating states.

For example, the diffractive mirror 2070 on the left side of the eyepiece waveguide 2000 generally propagates the beams incident from the x- direction back through the OPE region 2050 in the x- direction. It can be diffracted into the propagation state represented by the FOV rectangle at the time position. Similarly, the diffractive mirror 2070 at the bottom of the eyepiece waveguide 2010 is generally incident from the -y- direction so that they travel back through the OPE region 2050, generally in the y- direction. , Can be diffracted into the propagation state represented by the FOV rectangle at 12 o'clock.

FIG. 20L illustrates the k-space action of the bottom diffraction mirror 2070. As shown in the k-space schematic, the bottom diffractive mirror 2070 can be designed with a period that is half that of the grid in the ICG region 2040. This finer period results in a bottom diffractive mirror with an associated lattice vector twice as long as that of the ICG region 2040. Therefore, the bottom diffractive mirror can translate the FOV rectangle from the 6 o'clock position to the 12 o'clock position in the k-space ring. Although illustrated for eyepiece waveguide 2000, the same technique (ie, spatial variation in diffraction efficiency in the OPE, MPE, EPE regions, etc., and the use of diffraction mirrors along the peripheral edges) is also described herein. Can be used in combination with any of the other embodiments described in.

FIG. 20M illustrates an exemplary embodiment of eyeglasses 70 incorporating one or more instances of eyepiece waveguide 2000. A first instance of the eyepiece waveguide 2000 is integrated into the left viewing portion of the spectacle 70, while a second instance of the eyepiece waveguide 2000 is integrated into the right viewing portion. In the illustrated embodiment, each waveguide 2000 is about 50 × 30 mm ² , but many different sizes can be used. Each waveguide 2000 can be accompanied by a separate projector 2020 that projects the image into the corresponding waveguide. Assuming that the eyepiece waveguide is made from a material with a refractive index of 1.8, some embodiments of the eyepiece waveguide 2000 achieve a FOV with a size of 90 ° × 45 °. Although it is possible, some embodiments of the eyepiece waveguide meet the typical design constraints of eyebox volume (part of the FOV is delivered to both sides of the eyepiece waveguide and properly It may be advantageous to provide a sized eyebox), designed for smaller FOVs of about 60 ° x 45 ° to avoid net door artifacts resulting from sparsely spaced output beams. May be good.

FIG. 20N illustrates another exemplary embodiment of the spectacle 70 that incorporates one or more instances of the eyepiece waveguide 2000. This embodiment of the spectacle 70 is similar to that shown in FIG. 20M, but the orientation of the waveguide 2000 and the accompanying projector 2020 is rotated 90 ° towards the vine of the spectacle 70. In this configuration, some embodiments of the eyepiece waveguide 2000 have a size of 45 ° × 90 °, assuming that the eyepiece waveguide is made of a material with a refractive index of 1.8. Although it is possible to achieve the FOV of, some embodiments may be designed for smaller FOVs of about 45 ° × 60 ° to meet other design constraints.

FIG. 21A illustrates another embodiment of an eyepiece waveguide 2100 with an MPE region 2150 that is overlapped by the EPE region 2160. Similar to the eyepiece waveguide 2000 shown in FIG. 20A, the eyepiece waveguide 2100 shown in FIG. 21A is larger than the range of propagation angles that can be supported by the guided propagation mode in the thickness direction of the waveguide. Gain, extended vision can be achieved. The eyepiece waveguide 2100 has a first surface 2100a and a second surface 2100b. Further, as discussed below, different diffraction features can be formed on or within the opposite surfaces 2100a, 2100b of the eyepiece waveguide 2100. The two surfaces 2100a and 2100b of the eyepiece waveguide 2100 are shown in FIG. 21A so as to be displaced relative to each other in the xy plane. However, this is for illustration purposes only and it is possible to show different diffractive features formed on or within each surface. It should be understood that the first surface 2100a and the second surface 2100b are aligned with each other in the xy plane. In addition, MPE regions 2150 and EPE regions 2160 are shown to be exactly the same size and exactly aligned in the xy plane, but in other embodiments they have somewhat different sizes. It may be partially inconsistent. In some embodiments, the MPE region 2150 and the EPE region 2160 overlap each other by at least 70%, at least 80%, at least 90%, or at least 95%.

Like the eyepiece waveguide 2000 shown in FIG. 20A, the eyepiece waveguide 2100 shown in FIG. 21A includes an MPE region 2150 and an EPE region 2160. Unlike the eyepiece waveguide 2000 shown in FIG. 20A, the eyepiece waveguide 2100 shown in FIG. 21A is not a single ICG region but two ICG regions located on opposite sides of the MPE / EPE region. Includes 2140a and 2140b. Each of the ICG regions 2140a and 2140b can have its own associated projector. Each of the two projectors can input a sub-part of the complete input image FOV into the eyepiece waveguide 2100. Therefore, the ICG regions 2140a and 2140b can also be used to internally couple the input beams corresponding to the subparts of the FOV, respectively. Those subparts can then be combined in the exit pupil of the eyepiece waveguide 2100.

The left ICG region 2140a receives a set of first input beams corresponding to the first sub-part of the FOV from the first projector device, while the right ICG region 2140b corresponds to the second sub-part of the FOV. Receives a set of 2 input beams from the 2nd projector device. The first and second subparts of the FOV may be unique, or they may partially overlap. The first set of input beams is projected towards the left ICG region 2140a, generally along the -z- direction, but can be centered around the input beam with the propagating component in the -x- direction. The second set of input beams, on the other hand, is projected toward the right ICG region 2140b, generally along the -z- direction, but centered around the input beam with the propagating component in the + x- direction. obtain. The left ICG region 2140a diffracts the first set of input beams so that at least part of it propagates in the + x- direction, and the right ICG region 2140b propagates at least part of it in the -x- direction. Diffract the second set of input beams to enter the guided mode. Thus, both sets of first and second input beams corresponding to the first and second subparts of the FOV are directed towards the MPE region 2150, where they are located between the left and right ICG regions 2140a and 2140b. It is coupled into the eyepiece waveguide 2100 so that it propagates.

Similar to the eyepiece waveguide 2000 shown in FIG. 20A, the eyepiece waveguide 2100 shown in FIG. 21A also has an MPE region 2150 formed on or within the first side 2100a of the waveguide. , Can include overlapping EPE regions 2160 formed on or within the second side 2100b of the waveguide. The MPE region 2150 in the eyepiece waveguide 2100 shown in FIG. 21A can be similar to the MPE region 2050 in the eyepiece waveguide 2000 shown in FIG. 20A. That is, the MPE region 2150 can include a plurality of diffraction features that exhibit periodicity along the plurality of axes. Similarly, the EPE region 2160 in the eyepiece waveguide 2100 shown in FIG. 21A can be similar to the EPE region 2060 in the eyepiece waveguide 2000 shown in FIG. 20A. That is, the EPE region 2160 is
It can include a diffraction grating whose periodic axis is orthogonal to that of the two ICG regions 2140a and 2140b. The effects of MPE regions 2150 and EPE regions 2160 in FIG. 21A can also be similar to those of MPE regions 2050 and EPE regions 2060 in FIG. 20A, as shown in FIG. 21B-21D.

FIG. 21B is a k-space schematic KSD1 illustrating the k-space effect of the eyepiece waveguide 2100 over a set of first input beams corresponding to the first subpart of the FOV of the input image. The FOV rectangle centered on the origin of the KSD1 represents a beam of light corresponding to the fully input image FOV to be projected towards the user's eye by the eyepiece waveguide 2100. The size of the FOV rectangle as a whole has dimensions up to about twice as large as the width of the k-space ring. Therefore, the eyepiece waveguide 2100 shown in FIG. 21A is designed to have an improved FOV similar to the embodiments shown in FIGS. 19 and 20A. However, the first set of input beams projected towards the left ICG region 2140a corresponds only to the shaded sub-parts of the FOV rectangle. As shown in FIG. 21B, the shaded portion of the FOV rectangle corresponding to the first set of input beams is the left portion of the FOV rectangle. Since the center of the shaded portion of the FOV rectangle is offset from the origin of the k-space schematic in the -k _x- direction, the set of first input beams from the first projector is exactly in the -z- direction. Rather than centering the beam propagating to (which would be the case if the shaded portion of the FOV rectangle is centered around the origin of the k-space schematic), rather the propagating component in the -x- direction. It is centered around the accompanying oblique beam.

The left ICG region 2140a can be designed so that its lattice vector is oriented in the ± _kx− direction. The action of the left ICG region 2140a in k-space is to translate the shaded left portion of the FOV rectangle from the center of the k-space schematic to the 3 o'clock position in the k-space ring. This will propagate the diffracted beam generally in the x- direction towards the MPE region 2150. In some embodiments, the shaded left portion of the FOV rectangle can be configured to be more than half of the FOV rectangle. Also, in some embodiments, the left ICG region 2140a can be designed to translate the center of the FOV rectangle with respect to any radial position from the midpoint of the k-space ring to the outer boundary of the ring. .. Further, the left ICG region 2140a can be designed so that the magnitude of its lattice vector copies the FOV rectangle to a position where the shaded portion fits perfectly within the k-space ring at the 3 o'clock position. This can be accomplished, for example, by setting the magnitude of the ICG grid vector to exceed the distance from the origin of the k-space schematic to the midpoint of the k-space ring. Since the shaded portion of the FOV rectangle at 3 o'clock is completely within the k-space ring, all sets of first input beams corresponding to the first subpart of the FOV enter propagating induction mode. The FOV rectangle at 3 o'clock in the k-space ring has a right portion extending outside the ring, whereas this portion of the FOV rectangle is not necessarily provided by its associated projector in the left ICG region 2140a. Corresponds to the input beam, which is not part of the first subpart of the FOV.

The left ICG region 2140a can also diffract a portion of the first set of input beams in the opposite direction (ie, move the FOV rectangle parallel to the 9 o'clock position of the k-space ring), but the eyepiece guide. In the illustrated embodiment of the wave guide 2100, those particular diffracted beams will simply exit from the edge of the waveguide.

The MPE region 2150 contains a plurality of diffraction features having a plurality of periodic axes. In some embodiments, the MPE region 2150 can resemble the MPE region 2050 illustrated and discussed with respect to FIGS. 20A-20M. For example, the MPE region 2150 can have a plurality of associated lattice vectors that can translate the FOV rectangle from the 3 o'clock position to any of the 6 o'clock, 9 o'clock, and 12 o'clock positions of the k-space ring. .. As shown in FIG. 21B, the shaded portion of the FOV rectangle at 9 o'clock in the k-space ring is truncated and all beams of light associated with the first sub-part of the FOV are necessarily identified. It means that it does not exist in the propagation state of.

During the additional interaction with the MPE region 2150, the FOV rectangle can be translated back and forth between any of the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions. This is represented by a double-headed arrow between those propagation states within KSD1. Thus, the first set of input beams can be replicated throughout the MPE region 2150 by undergoing multiple interactions with its diffraction features, as described herein. This is indicated by an arrow in the OPE region 2150 of the eyepiece waveguide 2100 in FIG. 21A.

Since the EPE region 2160 overlaps the MPE region 2150 in the xy plane of the eyepiece waveguide 2100, the duplicated light beams also have their first diffused through the waveguide and through total internal reflection. As it reciprocates and reflects between the surface 2100a and the second surface 2100b, it interacts with the EPE region 2160. Each time one of the duplicated light beams interacts with the EPE region 2160, a portion of its power is diffracted as indicated by the arrow in the EPE region 2160 of the eyepiece waveguide 2100 in FIG. 21A. , Outerly coupled towards the user's eye.

In some embodiments, the EPE region 2160 comprises a diffraction grating whose lines are oriented perpendicular to the lines of the diffraction gratings that make up the ICG regions 2140a and 2140b. In this particular embodiment, the EPE region 2160 extends in the x- direction because the ICG regions 2140a and 2140b have grid lines extending in the y- direction and periodically repeating in the x- direction. , Has a grid line that is periodically repeated in the y- direction. Again, within the EPE region 2160 to help ensure that the light beam will interact with the MPE region 2150 before being coupled out of the eyepiece waveguide 2100 by the EPE region 2160. It is advantageous that the grid lines are oriented perpendicular to the grid lines in the ICG regions 2140a and 2140b.

FIG. 21B also illustrates the k-space effect of the EPE region 2160 on the first set of beams corresponding to the first subpart of the FOV. As already discussed, the beam of light propagates through the MPE region 2150 in any of the directions indicated by the FOV rectangles located at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock on the k-space ring. be able to. Further, since the EPE region 2160 overlaps with the MPE region 2150, the beam of light in any of these propagation states can interact with the EPE region and be externally coupled from the eyepiece waveguide 2100. Since the periodic axis of the diffraction grating in the EPE region 2160 points in the ± _ky − direction, the lattice vector associated with the EPE region also points in the same direction. FIG. 21B shows how the EPE region 2160 is therefore translated so that the FOV rectangles located at 12 and 6 o'clock positions on the k-space ring return to the origin of the k-space schematic. Thus, the EPE region 2160 can only externally couple the beam of light in either of those two propagating states. As shown in FIG. 21B, when the FOV rectangle is finally translated back to the center of the k-space schematic KSD1, the first set of beams constitutes the first subpart of the FOV. Are all present and projected towards the user's eye.

FIG. 21C is a k-space schematic KSD2 illustrating the k-space effect of the eyepiece waveguide 2100 over a set of second input beams corresponding to the second subpart of the FOV of the input image. Again, the FOV square centered to the origin of the KSD2 represents a beam of light corresponding to the complete input image to be projected towards the user's eye by the eyepiece waveguide 2100. However, the second set of input beams projected towards the right ICG region 2140b corresponds only to the shaded sub-parts of the FOV rectangle. As shown in FIG. 21C, the shaded portion of the FOV rectangle corresponding to the second set of input beams is the right portion of the FOV rectangle. Since the center of the shaded part of the FOV rectangle is offset in the + kx-direction from the origin of the _k -space schematic, the set of second input beams from the second projector propagates exactly in the -z- direction. Rather than centering on the beam (which would be the case if the shaded portion of the FOV rectangle is centered on the origin of the k-space schematic), rather an oblique beam with a propagating component in the + x- direction. Centered as the center.

In the illustrated embodiment, the action of the right ICG region 2140b in the k-space is to translate the right shaded portion of the FOV rectangle from the center of the k-space schematic to the 9 o'clock position. As shown, the right ICG region 2140b can be designed so that its lattice vector is oriented in the ± _kx− direction. This will propagate a portion of the diffracted beam in the -x- direction towards the MPE region 2150. In some embodiments, the shaded right portion of the FOV rectangle can be configured to be more than half of the FOV rectangle. Also, in some embodiments, the right ICG region 2140b can be designed to translate the center of the FOV rectangle with respect to any radial position from the midpoint of the k-space ring to the outer boundary of the ring. .. Further, the right ICG region 2140b can be designed so that the magnitude of its lattice vector copies the FOV rectangle to a position where the shaded portion fits perfectly within the k-space ring at 9 o'clock. .. This can be done, for example, by designing the ICG so that the magnitude of its lattice vector exceeds the distance from the origin of the k-space schematic to the midpoint of the k-space ring. Since the shaded portion of the FOV rectangle at 9 o'clock is completely within the k-space ring, all sets of second input beams corresponding to the second subpart of the FOV enter propagating induction mode. The FOV rectangle at 9 o'clock in the k-space ring has a left portion extending outside the ring, whereas this portion of the FOV rectangle corresponds to the input beam, which is not necessarily the projector associated with it. Not part of the second subpart of the FOV projected into the right ICG region 2140b by.

The right ICG region 2140b can also diffract a portion of the second set of input beams in the opposite direction (ie, move the FOV rectangle parallel to the 3 o'clock position of the k-space ring), but the eyepiece guide. In the illustrated embodiment of the wave guide 2100, those particular diffracted beams will simply exit from the edge of the waveguide.

As already discussed, the MPE region 2150 is a plurality of associated lattice vectors that can translate the FOV rectangle from the 9 o'clock position to any of the 6 o'clock, 3 o'clock, and 12 o'clock positions of the k-space ring. Can have. As shown in FIG. 21C, the shaded portion of the FOV rectangle at 3 o'clock in the k-space ring is truncated and all beams of light associated with the second sub-part of the FOV are not necessarily specific. It means that it does not exist in the propagation state.

During the additional interaction with the MPE region 2150, the FOV rectangle can be translated back and forth between any of the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions. This is represented by a double-headed arrow between those propagation states within KSD2. Thus, the second set of input beams can be replicated throughout the MPE region 2150 by undergoing multiple interactions with its diffraction features, as described herein. Again, this is indicated by the arrow in the OPE region 2150 of the eyepiece waveguide 2100 in FIG. 21A.

FIG. 21C also illustrates the k-space effect of the EPE region 2160 on the second set of beams corresponding to the second subpart of the FOV. As already discussed, the EPE region 2160 translates the FOV rectangles located at the 12 o'clock and 6 o'clock positions of the k-space ring back to the origin of the k-space schematic. Thus, the EPE region 2160 can only externally couple the beam of light in either of those two propagating states. As shown in FIG. 21C, when the FOV rectangle is finally translated back to the center of the k-space schematic KSD2, a second set of beams constituting a second subpart of the FOV. Are all present and projected towards the user's eye.

21D is a k-space schematic KSD3 summarizing the k-space action of the eyepiece waveguide 2100 shown in FIG. 21A. This is essentially a superposition of the k-space schematics shown in FIGS. 21B and 21C. Again, the k-space schematic in FIG. 21D shows a FOV rectangle with at least one dimension larger than the width of the k-space ring. In some embodiments, at least one dimension of the FOV rectangle can be up to about twice as large as the width of the k-space ring. In the illustrated embodiment, the horizontal dimension of the FOV rectangle is greater than the width of the k-space ring. Although the eyepiece waveguide 2100 is illustrated to provide an extended horizontal field of view, the same technique can also be used to extend the vertical field of view.

As shown in FIG. 21D, using separate projectors and ICG regions 2140a, 2140b, the first and second sets of input beams are projected separately into the eyepiece waveguide 2100, although Once the various FOV rectangles from the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions of the k-spatial ring are translated back to the origin of the k-spatial schematic and thus external towards the user's eye. Once combined, all the beams required to form a complete image FOV are present. Also, the first and second subparts of the FOV are aligned in k-space with the same relative position to each other, as in a fully input FOV.

FIG. 21E illustrates an exemplary embodiment of eyeglasses 70 incorporating one or more instances of eyepiece waveguide 2100. FIG. 21F illustrates an exemplary FOV corresponding to the spectacles 70 in FIG. 21E. A first instance of the eyepiece waveguide 2100 is integrated into the left viewing portion of the spectacle 70, while a second instance of the eyepiece waveguide 2100 is integrated into the right viewing portion. In the illustrated embodiment, the eyepiece waveguides 2100 are each about 50 × 30 mm ² , but many different sizes can be used. Each eyepiece waveguide 2100 can be accompanied by two separate projectors 2120a, 2120b, each projecting a sub-part of the FOV into the corresponding waveguide, as just discussed. In some embodiments, the first projector 2120a for each waveguide 2100 is capable of inputting light to the eyepiece side of the waveguide 2100, while the second projector 2120b is capable of inputting light to the eyepiece. It can be input to the nasal side of the waveguide. For eyepiece waveguides made from a material with a refractive index of n = 1.8, the projectors 2120a and 2120b are 50 ° × 60, respectively, depending on other design constraints such as eyebox size and screen artifacts. You can enter sub-parts of the FOV that are greater than or equal to °. Further, the complete FOV can have a size of 100 ° × 60 ° or more. This is shown as the monocular eyepiece FOV configuration illustrated in FIG. 21F. As illustrated by the matching shading, in this configuration the first projector 2120a (temple side) can be used to project the nasal side of the complete FOV and the second projector 2120b (nasal side). ) Can be used to project the temple side of a complete FOV. Note that the crosshairs indicate one possible pupil alignment, but others can also be used.

Alternatively, two instances of the eyepiece waveguide 2100 and the spectacles 70 can both be used to provide a binocular FOV. For example, each eyepiece waveguide 2100 can project a FOV as shown in the monocular eyepiece configuration. However, the FOV projected by the two eyepiece waveguides 2100 can at least partially overlap. FIG. 21F illustrates a case where the FOVs projected by the two eyepiece waveguides 2100 are horizontally overlapped by 50 ° to provide a 150 ° × 60 ° overall binocular FOV. The binocular FOV can be even greater if less overlap is provided between the FOVs of the two eyepiece waveguides 2100. In a binocular FOV configuration, as illustrated by the matching shading, the first projector 2120a (temple side) can be used to project the central portion of the binocular FOV and the second projector 2120b (nose). Sides) can be used to project the sides of a binocular FOV.

FIG. 21G illustrates the k-space effect of another embodiment of the eyepiece waveguide 2100 shown in FIG. 21A. In this embodiment, the size of the FOV rectangle can exceed the width of the k-space ring in both k _x and _ky dimensions. In FIG. 21G, the darker shaded portion of the FOV rectangle corresponds to the right portion of the FOV, while the lighter shaded portion of the FOV rectangle corresponds to the left portion of the FOV. The left and right ICG regions 2140a and 2140b can be designed to shift the FOV rectangle to the 3 o'clock and 9 o'clock positions, as already discussed, using the lattice vector. The magnitude of the lattice vector in the ICG region can be such that the center of the perfect FOV rectangle is displaced, for example, to any radial position between the midpoint of the k-space ring and the perimeter of the ring. .. Also, the MPE region can be designed to shift the complete FOV rectangle to the 3 o'clock, 6 o'clock, 9 o'clock, and 12 o'clock positions, as already discussed, using the lattice vector. However, the magnitude of the lattice vector in the MPE region 2150 is also such that the center of the perfect FOV rectangle is biased, for example, to any radial position between the midpoint of the k-space ring and the perimeter at those locations of the ring. Can be designed to be transferred. Therefore, even at 12 o'clock and 6 o'clock positions, which are located along the axis of the shorter dimension of the FOV rectangle, part of the FOV rectangle is of the k-space ring so that part of the rectangle is truncated. It can extend beyond the perimeter.

The guided beam corresponding to the apex portion of the FOV rectangle can be lost, but all the beams required to construct a complete FOV are all represented by the 3 o'clock, 6 o'clock, 9 o'clock and 12 o'clock positions. Considering the propagation state, it still exists in the waveguide. The left FOV (brighter shaded rectangle) is fully preserved at 9 o'clock, while the bottom portion is preserved at 12 o'clock and the top portion is preserved at 6 o'clock. Similarly, the right FOV (darker shaded rectangle) is fully preserved at 3 o'clock, while the bottom portion is preserved at 12 o'clock and the top portion is preserved at 6 o'clock. Thus, when the FOV rectangle is translated back to the origin of the k-space schematic and externally coupled towards the user's eye, all the beams needed to form a complete FOV are present and complete. The FOV can be recreated. The extension of the FOV rectangle in multiple directions is further discussed in FIGS. 22A-22E.

FIG. 22A shows the eyepiece waveguide 2200, which can project FOV extended in two directions beyond the range of propagation angles that can be supported in the guided propagation mode in the thickness direction of the eyepiece waveguide. An embodiment is illustrated. The eyepiece waveguide 2200 includes a left ICG region 2240a provided between a first pair of upper OPE regions and bottom OPE regions 2250a1 and 2250a2. It also includes the right ICG region 2240b provided between the top OPE region and the bottom OPE region 2250b1 and 2250b2 of the second pair. Finally, the MPE region 2250c and the overlapping EPE region 2260 are provided between the first and second ICG regions 2240a, 2240b and their separate OPE regions. The MPE region 2250c can be provided on or within the first surface 2200a of the eyepiece waveguide 2200 (shown in FIG. 22A), while the EPE region 2260 can be provided in the waveguide (shown in FIG. 22B). ) Can be provided on or within a second surface. The MPE region 2250c and the EPE region 2260 are shown as identical sizes and are precisely aligned in the xy plane, but in other embodiments they may have somewhat different sizes and are partially. It may be inconsistent. In some embodiments, the MPE region 2250c and the EPE region 2260 overlap each other by at least 70%, at least 80%, at least 90%, or at least 95%.

The left ICG region 2240a and the first pair of top and bottom OPE regions 2250a1 and 2250a2 function similarly to those illustrated and described with respect to FIG. That is, the projector or other input device projects a set of beams corresponding to the input image FOV towards the left ICG region 2240a, generally along the −z— direction. The left ICG region 2240a has a grid line extending in the x- direction and periodically repeating in the y- direction. The left ICG region 2240a thus couples the input beam of light to the +1 and -1 diffraction orders, which are generally towards the upper OPE region 2250a1 in the + y- direction and lower in the -y- direction. It propagates toward the OPE region 2250a2. The upper and lower OPE regions 2250a1, 2250a2 of the first set replicate their input beams, as discussed herein, and then generally towards the MPE / EPE region in the x- direction. , Induces a set of duplicate output beams.

The right ICG region 2240b and the second pair of top and bottom OPE regions 2250a1 and 2250a2 function in the same manner but are mirrored around the y-axis. That is, the projector or other input device projects the same set of input beams towards the right ICG region 2240b, generally along the −z— direction. The right ICG region 2240b also has grid lines extending in the x- direction and periodically repeating in the y- direction. The right ICG region 2240b therefore also couples the input beam of light to the +1 and -1 diffraction orders, which are generally in the + y- direction towards the upper OPE region 2250b1 and in the -y- direction. Propagate towards the lower OPE region 2250b2. The upper and lower OPE regions 2250b1 and 2250b2 of the second set replicate their input beams and then generally guide a set of duplicate output beams towards the MPE / EPE region in the -x- direction. ..

FIG. 22C illustrates the k-space action of the ICG regions 2240a, 2240b and the OPE regions 2250a1, 2250a2, 2250b1, 2250b2 in the eyepiece waveguide embodiment 2200 shown in FIG. 22A. Specifically, the left panel (KSD1a) of FIG. 22C illustrates the k-space action of the left ICG region 2240a and its associated first set of top and bottom OPE regions 2250a1 and 2250a2. The right panel of 22C (KSD1b) illustrates the k-space action of the right ICG region 2240b and its associated second set of top and bottom OPE regions 2250b1 and 2250b2.

The set of input beams corresponding to the FOV of the input image is projected towards both the left ICG region 2240a and the right ICG region 2240b. This set of input beams is illustrated in KSD1a and KSD1b as FOV squares centered on the individual origins of these k-space schematics. Unlike the previously illustrated improved FOV embodiment, which shows only a single dimension of the FOV that is greater than the width of the k-space ring, both dimensions of the FOV square in KSD1a and KSD1b are greater than the width of the k-space ring. big. In some embodiments, both dimensions of the FOV square can be up to about twice as large as the width of the k-space ring. The present embodiment is illustrated using FOV squares with equal horizontal and vertical FOVs, but this is not a requirement and the horizontal and vertical FOVs do not necessarily have to be equal. The embodiment of the eyepiece waveguide 2200 shown in FIG. 22A assumes an eyepiece waveguide with a refractive index of 1.8 (enclosed by air) and other eyebox sizes and Amito artifacts and the like. Depending on the design constraints, it may be possible to achieve a FOV with a magnitude of 100 ° × 60 ° or more (eg, 100 ° × 90 °).

In _KSD1a , the FOV square is translated in the ± ky-direction in k-space by the lattice vector associated with the left ICG region 2240a. Similarly, in KSD1b, the FOV square is k-by the lattice vector associated with the right ICG region 2240b.
It is translated in the ± _ky -direction in space. In both cases, after being internally coupled into the eyepiece waveguide 2200 by the ICG regions 2240a and 2240b, the input beam is represented by the translated FOV squares at the 12 o'clock and 6 o'clock positions of the k-space ring. It is in a propagating state. As shown in both KSD1a and KSD1b, the FOV squares at these positions are truncated because they do not fit entirely within the k-space ring. Only those beams corresponding to the shaded lower portion of the FOV square at 12 o'clock enter guided propagation mode. On the other hand, only those beams corresponding to the shaded upper portion of the FOV square at 6 o'clock enter the guided propagation mode.

KSD1a also exhibits the k-space effect of the top OPE and bottom OPE regions 2250a1 and 2250a2 of the first set. These OPE regions include a diffraction grating designed to have an associated lattice vector that translates the FOV square from the 12 o'clock and 6 o'clock positions to the 3 o'clock position. The beam at 3 o'clock generally propagates in the x- direction towards the MPE / EPE region.

The beam corresponding to the upper part of the FOV square at 3 o'clock in k-space is provided by the FOV square previously located at 6 o'clock, while the beam corresponding to the lower part of the FOV square at 3 o'clock. Is provided by a FOV square previously located at 12 o'clock. However, the FOV square is again too large to fit entirely within the k-space ring at 3 o'clock. The FOV square is therefore truncated, but this time the beam corresponding to the shaded left portion of the FOV square remains in guided propagation mode, while the beam corresponding to the unshaded right portion of the FOV square remains. , K-Outside the space ring, lost.

The k-space action of the top OPE region and bottom OPE region 2250b1, 2250b2 of the second set is a mirrored version of the k-space action of the top OPE region and bottom OPE region _2250a1 , 2250a2 of the first set (ky-. With the axis as the center). Thus, as shown in KSD1b, the top OPE and bottom OPE regions 2250b1 and 2250b2 of the second set will eventually produce a truncated FOV square at 9 o'clock on the k-space ring, where The beam corresponding to the shaded right part of the square propagates in guided mode towards the MPE / EPE region, while the beam corresponding to the unshaded left part of the FOV square is outside the k-space ring and is lost. Will be done.

FIG. 22D illustrates the k-space effect of the MPE region 2250c in the eyepiece waveguide embodiment 2200 shown in FIG. 22A. Specifically, the left panel (KSD2a) of FIG. 22D is the MPE region 2250c overlaid on the beams received from the left ICG region 2240a and its associated first set of top and bottom OPE regions 2250a1 and 2250a2. While illustrating the k-space effect of, the right panel (KSD2b) is an MPE exerted on the beams received from the right ICG region 2240b and its associated second set of top and bottom OPE regions 2250b1 and 2250b2. The k-space action of region 2250c is illustrated.

The MPE region 2250c can act in the same manner as described for the MPE regions 2050 and 2150 in FIGS. 20A and 21A. That is, as already discussed, the MPE region 2250c can consist of a 2D array of diffraction features that exhibits periodicity in multiple directions. The MPE region 2250c therefore has a plurality of associated lattice vectors that can translate the FOV square back and forth within the 3 o'clock, 6 o'clock, 9 o'clock, and 12 o'clock positions of the k-space ring. This is represented by a double-headed arrow between the propagation states within KSD2a and KSD2b. In this embodiment, the lattice vectors G and H of the MPE region 2250c have the FOV extended beyond the width of the k-space ring in both dimensions and therefore F.
Since the centers of the OV squares can be translated into the same radial location in the _k -space ring in both the kx and _ky directions, they can be perpendicular to each other.

As already discussed, the beams arriving from the left ICG region 2240a and the top and bottom OPE regions 2250a1, 2250a2 of the first set to the MPE region 2250c are represented by the FOV square at 3 o'clock in the k-space ring. Is in a propagating state. Only the beam corresponding to the shaded left portion of the FOV square is present in this propagating state. As shown in KSD2a, when the MPE region 2250c diffracts these beams into the propagating state represented by the FOV square at 12 o'clock, the FOV square is again truncated and into the shaded lower left portion of the FOV square. Only the corresponding beam remains in the guided propagation state. On the other hand, when the MPE region 2250c diffracts the beam from the propagation state represented by the FOV square at 3 o'clock to the propagation state represented by the FOV square at 6 o'clock, the FOV square is again truncated and FOV. Only the beam corresponding to the shaded upper left part of the square remains in the guided propagation state. Finally, when the FOV square is translated from either the 12 o'clock position or the 6 o'clock position of the k-space ring to the 9 o'clock position, the FOV square is truncated again, which is possible. , Neither of the beams can be left in the induced propagation state. This is indicated by an unshaded FOV square at 9 o'clock in KSD2a.

KSD2b is a mirror image of KSD2a centered on the _y -axis. KSD2b exhibits the k-space effect of the MPE region 2250c exerted on the beam of light arriving from the right ICG region 2240b and the upper and bottom OPE regions 2250b1 and 2250b2 of the second set. These beams are in the propagating state represented by the FOV square at 9 o'clock in the k-space ring. Only the beam corresponding to the shaded right portion of the FOV square is present in this propagating state. As shown in KSD2b, when the MPE region 2250c diffracts these beams into the propagation state represented by the FOV square at 12 o'clock, the FOV square is again truncated and the shaded lower right portion of the FOV square. Only the beam corresponding to remains in the guided propagation state. On the other hand, when the MPE region 2250c diffracts the beam from the propagation state represented by the FOV square at 9 o'clock to the propagation state represented by the FOV square at 6 o'clock, the FOV square is again truncated and FOV. Only the beam corresponding to the shaded upper right part of the square remains in the guided propagation state. Finally, when the FOV square is translated from either the 12 o'clock position or the 6 o'clock position of the k-space ring to the 3 o'clock position, the FOV square is truncated again, which is possible. , Neither of the beams can be left in the induced propagation state. This is indicated by an unshaded FOV square at 3 o'clock in KSD2b.

Thus, the beam, replicated by propagation through the MPE region 2250c, corresponds to the four subparts of the FOV, the first subpart corresponding to the upper left part of the FOV square, the upper right part of the FOV square. It is divided into a second sub-part, a third sub-part corresponding to the lower left portion of the FOV square, and a fourth sub-part corresponding to the lower right portion of the FOV square. These subparts of any pair of full FOVs can partially overlap. In other words, any pair of these subparts of the FOV can include a beam that corresponds to one or more of the same input beams. Alternatively, the subparts of the FOV can also be unique, without duplication. In either case, the subparts of the FOV are combined to recreate the complete FOV in the exit pupil of the eyepiece waveguide 2200. This is shown in FIG. 22E.

FIG. 22E illustrates the k-space action of the EPE region 2260 in the eyepiece waveguide embodiment 2200 shown in FIG. 22A. The EPE region 2260 can function in the same manner as described for the EPE regions 2060 and 2160 in FIGS. 20A and 21A. As discussed herein, the EPE region 2260 overlaps the MPE region 2250c, so that the beam of light propagating within the MPE region also interacts with the EPE region and is external from the eyepiece waveguide 2200. Can be combined. The EPE region 2260 includes a diffraction grating whose periodic axis is aligned with that of the left ICT region 2240a and the right ICG region 2240b. In the illustrated embodiment, the periodic axis for the EPE region 2260 points in the ± _ky − direction. The EPE region 2260 therefore has an associated lattice vector, which also points in the same direction and has a FOV square located at 12 and 6 o'clock positions on the k-space ring as the origin of the k-space schematic. Translate to return to. FIG. 22E shows that when this happens, the four subparts of the FOV are assembled to recreate the complete FOV. All the beams required to construct a complete image FOV are present. Also, the four subparts of the FOV are aligned in k-space with the same relative position to each other, as in a full input FOV.

(Eyepiece waveguide designed to work with an angled projector)
Many of the eyepiece waveguide embodiments described herein are designed to work with a projector (or other image input device) whose optical axis intersects the ICG region at a vertical angle. .. In such an embodiment, the central input beam (corresponding to the center point of the input image) is vertically incident on the ICG region and the input beam corresponding to the top / bottom and left / right parts of the input image is symmetrical. It is incident on the ICG region at an angle. However, in some embodiments, the eyepiece waveguide may be designed to work with an angled projector (or other image input device). FIG. 23 illustrates an embodiment of such an embodiment.

FIG. 23 illustrates an exemplary embodiment of an eyepiece waveguide 2300 designed to function with an angled projector. The eyepiece waveguide 2300 includes an ICG region 2340, left and right OPE regions 2350a and 2350b, and an EPE region 2360. The input beam from the projector is incident on the ICG region 2340 and coupled into the eyepiece waveguide 2300 in guided propagation mode. In this embodiment, the projector is oriented at a non-vertical angle with respect to the ICG region 2340. The central input beam 2341 from the projector is therefore incident on the ICG region 2340 at an oblique angle (eg, as illustrated in FIG. 13I). This results in deviations of the k-vectors in k-space for the input beam and no longer center them around the origin of the k-space schematic. As a result, the optical design of the ICG, OPE, and / or EPE regions, along with their physical shape, may need to be modified (eg, according to the principles described with reference to FIG. 14D), the k-space ring. The installation of the FOV rectangle within may also change, as discussed below.

The positive and negative diffraction orders from the ICG region 2340 then propagate to the left and right OPE regions 2350a and 2350b, respectively. The OPE region 2350 horizontally replicates the input beams and directs them towards the EPE region 2360 in a spatially dispersed fashion. The EPE region 2360 then further replicates the beams vertically and externally couples them towards the user's eye in a spatially dispersed fashion, as discussed elsewhere herein.

FIG. 23 includes a k-space schematic KSD illustrating the k-space action of the eyepiece waveguide 2300. As described in any of the specification, the FOV rectangle in the central portion of the k-space schematic corresponds to the input beam from the projector and the output beam from the eyepiece waveguide 2300. The FOV rectangle near the 4 o'clock and 8 o'clock positions in the k-space ring corresponds to the beam of light propagating from the ICG region 2340 to the OPE region 2350. Finally, the FOV rectangle at 6 o'clock in the k-space ring corresponds to a beam of light propagating downward from the OPE region 2350 to the EPE region 2360.

Since the projector is angled with respect to the ICG area 2340, the FOV rectangle corresponding to the input beam is not centered on the origin of the k-space schematic. Instead, in the illustrated embodiment, the FOV rectangle corresponding to the input beam is centered on the _{ky-axis but below the k x -} axis. This means that none of the input beams have a propagation direction with a component in the + y- direction. In other words, the input beam propagates downward from the projector toward the ICG region. The ICG region 2340 then translates the FOV rectangle horizontally into the _k -space ring in the ± kx-direction.

None of the induced light beams from the ICG region 2340 have a k-vector with a positive ky component (ie, the FOV rectangle is located below the _{k x -} axis), so the upper edge of the OPE region 2350. Can be horizontal as shown, as it does not need to adapt to a beam of light spreading upward in the + y- direction. This property of the OPE region 2350 may be advantageous in some embodiments as it may allow for a compact design. However, the horizontal upper edge of the OPE region 2350 is practiced by an angled image projector. However, angled image projectors can be associated with some disadvantages. For example, the eyepiece waveguide 2300 (including, for example, the optical design and / or physical layout of the lattice) is designed to receive input light from an upward angle and thus is an overhead source such as the sun or ceiling light fixture. Light from can also be coupled into the eyepiece waveguide. This can result in unwanted image features such as afterglow images, artifacts, and reduced contrast of those light sources superimposed on the displayed virtual content. Light from overhead sources can be blocked by including a visor, such as blocking the eyepiece waveguide 2300 from the ceiling light, but such a visor may not be bulky or aesthetically desirable. Therefore, an eyepiece waveguide designed to function with a vertical projector may be preferred as it may reduce or eliminate the need for a visor. In addition, with respect to projector designs angled upwards or downwards, the fact that the output beam also exits the waveguide at an angle similar to the input beam is that the eyepiece waveguide is the user's central line-of-sight vector. It means that it may need to be tilted relative to and / or placed above or below it rather than directly in front of the eye.

(Exemplary Embodiment)
In some embodiments, it is an eyepiece lens waveguide for an augmented reality display system, wherein the eyepiece lens waveguide is an input coupling formed on or within an optically transmissive substrate. A multidirectional region formed on or in a grid (ICG) region with an ICG region that receives an input beam of light and is configured to couple the input beam into a substrate as a guided beam. The pupil expander (MPE) region, the MPE region, has a plurality of diffraction features that exhibit periodicity along at least a first periodic axis and a second periodic axis, and guides the beam from the ICG region. An MPE region that receives and diffracts it in multiple directions to create multiple diffracted beams, and an ejection pupil expander (EPE) region that is formed on or within the substrate and is a diffracted beam. It comprises an EPE region that receives one or more of them from the MPE region and is positioned to externally couple them from an optically transmissive substrate as an output beam.

In a prior embodiment, the MPE region may comprise a two-dimensional grid pattern with distinct diffraction features.

In any of the prior embodiments, the MPE region may include cross grids.

In any of the prior embodiments, the MPE region may be configured to create a diffracted beam by diffracting a portion of the power of the guided beam from the ICG region in at least three directions.

In any of the prior embodiments, one of the three directions may correspond to a zero-order diffraction beam.

In any of the prior embodiments, two or more of the three directions may correspond to the primary diffraction beam.

In any of the prior embodiments, the three directions may be angularly separated by at least 45 degrees.

In any of the prior embodiments, the MPE and EPE regions cannot overlap and only one of the three directions of the diffracted beam can intersect the EPE region.

In any of the prior embodiments, one of the three directions may correspond to the direction from the ICG region to the MPE region.

In any of the prior embodiments, the MPE region may be configured to create a diffracted beam by diffracting a portion of the power of the guided beam from the ICG region in at least four directions.

In any of the prior embodiments, the four directions may be angularly separated by at least 45 degrees.

In any of the prior embodiments, the MPE region again diffracts the diffracted beam, which is still propagating within the MPE region after being initially diffracted, at multiple dispersal locations in the same direction. This may be configured to increase the number of diffracted beams.

In any of the prior embodiments, only a subset of the diffracted beams can propagate towards the EPE region.

In any of the prior embodiments, the EPE region may be positioned to receive only one of the diffracted beams propagating in one of a plurality of directions.

In any of the prior embodiments, those diffracted beams propagating towards the EPE region may have non-uniform spacing.

In any of the prior embodiments, some of the diffraction features in the MPE region may have a diffraction efficiency of 10% or less.

In any of the prior embodiments, the diffraction efficiency of the diffraction features in the MPE region may vary spatially.

In any of the prior embodiments, the ICG region may include a one-dimensional periodic lattice.

In any of the prior embodiments, the one-dimensional periodic lattice in the ICG region may be a blazed lattice.

In any of the prior embodiments, the EPE region may include a one-dimensional periodic lattice.

In any of the prior embodiments, the one-dimensional periodic lattice in the EPE region may include multiple lines curved to apply refractive power to the output beam.

In any of the prior embodiments, the input beam may be collimated and have a diameter of 5 mm or less.

In any of the prior embodiments, the MPE region and the EPE region cannot overlap.

In any of the prior embodiments, the optically transmissive substrate may be flat.

In any of the prior embodiments, the eyepiece waveguide may be incorporated into an eyepiece for an augmented reality display system.

In any of the prior embodiments, the eyepiece may be configured to display a color image in multiple depth planes.

In any of the prior embodiments, the ICG region may be configured to receive a set of input beams of a plurality of lights and combine the set of input beams into a substrate as a set of guided beams, of the guided beam. The set is at least partially associated with a set of k-vectors in k-space within the k-space ring associated with the eyepiece lens waveguide, and the k-space ring is within the eyepiece lens waveguide. Corresponding to the region in k-space associated with the guided propagation of, the MPE region may be configured to diffract a set of guided beams so as to create at least three sets of diffracted beams. A set of beams is at least partially associated with at least three sets of k-vectors at three different angular locations within the k-space ring.

In any of the prior embodiments, the set of k-vectors associated with the set of guided beams may be completely within the k-space ring.

In any of the prior embodiments, the set of k-vectors associated with the set of diffracted beams may be completely within the k-space ring.

In any of the prior embodiments, the set of k-vectors associated with the set of diffracted beams may be angularly spaced from each other within the k-space ring at least 45 degrees.

In any of the prior embodiments, the individual set of diffracted beams and the associated set of k-vectors cannot overlap with each other.

In one of the prior embodiments, one of the sets of k-vectors associated with the set of diffracted beams is at an angular position in the k-space ring corresponding to the direction from the ICG region to the MPE region. It may be located.

In one of the prior embodiments, one of the sets of k-vectors associated with the set of diffracted beams is at an angular position in the k-space ring corresponding to the direction from the MPE region to the EPE region. It may be located.

In any of the prior embodiments, the MPE region may be configured to diffract a set of guided beams so as to create at least four sets of diffracted beams, the set of diffracted beams being at least partially. , Is associated with at least four sets of k-vectors at four different angular positions in the k-space ring.

In one of the prior embodiments, while the diffracted beam propagates within the MPE region, the MPE region is such that its corresponding set of k-vectors transitions between three different locations within the k-space ring. It may be configured to further diffract the diffracted beam.

In any of the prior embodiments, the set of input beams may be associated with the input image.

In any of the prior embodiments, the input beam may correspond to the center of the input image and be vertically incident on the ICG region.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is configured to receive a set of input beams of light and combine the set of input beams into a substrate as a set of guided beams, the set of guided beams being at least partially the eyepiece lens waveguide. Associated with the set of k-vectors in k-space within the k-spatial ring associated with, the k-spatial ring is the region within k-space associated with guided propagation within the eyepiece lens waveguide. Corresponding to the ICG region and the multidirectional pupil expander (MPE) region formed on or within the substrate, the MPE region is positioned to receive a set of guided beams from the ICG region, at least. It is configured to diffract a set of guided beams so as to create three sets of diffracted beams, the set of diffracted beams being at least partially within the k-spatial ring at three different angle locations. An MPE region associated with at least three sets of k-vectors to be centered and an ejection pupil expander (EPE) region formed on or within a substrate, one of a set of diffracted beams. It comprises an EPE region that receives one from the MPE region and is positioned to externally couple them as an output beam from an optically transmissive substrate.

In a prior embodiment, the set of k-vectors associated with the set of guided beams may be completely within the k-space ring.

In any of the prior embodiments, the set of k-vectors associated with the set of diffracted beams may be completely within the k-space ring.

In any of the prior embodiments, the set of k-vectors associated with the set of diffracted beams may be angularly spaced from each other within the k-space ring at least 45 degrees.

In any of the prior embodiments, the individual set of diffracted beams and the associated set of k-vectors cannot overlap with each other.

In one of the prior embodiments, one of the sets of k-vectors associated with the set of diffracted beams is at an angular position in the k-space ring corresponding to the direction from the ICG region to the MPE region. It may be located.

In one of the prior embodiments, one of the sets of k-vectors associated with the set of diffracted beams is at an angular position in the k-space ring corresponding to the direction from the MPE region to the EPE region. It may be located.

In any of the prior embodiments, the MPE region may be configured to diffract a set of guided beams so as to create at least four sets of diffracted beams, the set of diffracted beams being at least partially. , Is associated with at least four sets of k-vectors in the k-space ring, centered at four different angular positions.

In one of the prior embodiments, while the diffracted beam propagates within the MPE region, the MPE region is diffracted such that its corresponding set of k-vectors transitions between three different locations within the k-space ring. It may be configured to further diffract the beam.

In any of the prior embodiments, the set of input beams may be associated with the input image.

In any of the prior embodiments, the MPE region may have a plurality of diffraction features that exhibit periodicity along at least a first periodic axis and a second periodic axis.

In any of the prior embodiments, the MPE region may comprise a two-dimensional grid pattern with distinct diffraction features.

In any of the prior embodiments, the MPE region may include cross grids.

In any of the prior embodiments, the input beams may each be collimated and have a diameter of 5 mm or less.

In any of the prior embodiments, the MPE region and the EPE region cannot overlap.

In any of the prior embodiments, the eyepiece waveguide may be incorporated into an eyepiece for an augmented reality display system.

In any of the prior embodiments, the eyepiece may be configured to display a color image in multiple depth planes.

In some embodiments, the eyepiece waveguide for the augmented reality display system is an input coupling region for receiving the input beam of light associated with the image, and the input beam of light is associated. An input coupling region with a pupil, a multidirectional pupil expander (MPE) region configured to expand the pupil in at least three directions, and an output beam of light associated with the image. It has an emission area.

In the prior embodiments, the MPE region may be configured to expand the pupil size in at least four directions.

In any of the prior embodiments, the MPE region and the exit region cannot overlap.

In any of the prior embodiments, the MPE region may create an aperiodic array of output pupils.

In any of the prior embodiments, the central beam of the set of input beams may be vertically incident on the ICG region.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is to receive a set of input beams of light, that set of input beams is associated with a set of k-vectors in k-space, and that a first set of guided beams and a first set of guided beams. By diffracting a set of input beams, such as to create a set of non-diffractive beams, the first set of guided beams is in the k-spatial ring associated with the eyepiece waveguide. Corresponding to the parallel movement subset of the k-vector, the first set of non-diffraction beams corresponds to the parallel movement subset of the k-vector, which is outside the k-space ring, and the k-space ring corresponds to the eyepiece waveguide. Corresponding to the region in the k-space associated with the guided propagation in the tube, and to create a separate set of second guided beams and a separate set of second non-diffraction beams of the input beam. To diffract the set, the second set of guided beams corresponds to a parallel moving subset of k-vectors within the k-space ring, and the second set of non-diffraction beams corresponds to the k-space. An ICG region and a first pupil expander region formed on or in the substrate that are configured to do things that are out of the ring and can correspond to a parallel movement subset of the k-vector. A first pupil expander region, located on or in a substrate, positioned to receive a set of first guided beams from the ICG region and configured to replicate them as a set of first duplicate beams. A second pupil expander region formed, positioned to receive a set of second guided beams from the ICG region and configured to replicate them as a set of second duplicate beams. A second pupil expander region and an exit region formed on or within the substrate, the exit region is positioned to receive a set of first and second duplicate beams, which are used as output beams. Configured to be externally coupled, the output beam comprises an exit region that represents the complete set of input beams.

In a prior embodiment, the first set of guided beams may correspond to a positive diffraction order in the ICG region and the second set of guided beams may correspond to a negative diffraction order.

In any of the prior embodiments, the translational moving subset of the k-vector associated with the first set of guided beams may be located at a first position in the k-space ring and the second guided beam. The translational subset of k-vectors associated with the set of may be located at a second position in the k-space ring opposite the first position.

In any of the prior embodiments, the center points of the first and second positions may be separated by 180 degrees.

In any of the prior embodiments, the first pupil expander region and the second pupil expander region are a subset of k-vectors and a second guided beam associated with a set of first guided beams, respectively. It may be configured to translate a subset of k-vectors associated with the set to adjacent positions in the k-space ring.

In any of the prior embodiments, the first set of guided beams and the second set of guided beams each represent only a subset of the input beams individually, but collectively may represent a complete set of input beams. ..

In any of the prior embodiments, the first pupil expander region and the second pupil expander region are a subset of k-vectors and a second guided beam associated with a set of first guided beams, respectively. It may be configured to translate a subset of k-vectors associated with the set to overlapping positions in the k-space ring.

In any of the prior embodiments, the first set of guided beams and the second set of guided beams each represent only a subset of the input beams individually, but collectively may represent a complete set of input beams. ..

In any of the prior embodiments, the set of k-vectors associated with the set of input beams may have a first dimension in the k-space that is greater than the width of the k-space ring.

In any of the prior embodiments, the first dimension may be up to twice as large as the width of the k-space ring.

In any of the prior embodiments, the first dimension may correspond to a field of view of at least 60 degrees.

In any of the prior embodiments, the set of k-vectors associated with the set of input beams may have a second dimension that is not greater than the width of the k-space ring.

In any of the prior embodiments, the set of input beams may be associated with the input image.

In any of the prior embodiments, the first and second pupil expander regions may comprise an orthogonal pupil expander (OPE) region.

In any of the prior embodiments, the exit region may comprise an exit pupil expander (EPE) region.

In any of the prior embodiments, the input beams may each be collimated and have a diameter of 5 mm or less.

In any of the prior embodiments, the first and second pupil expander regions cannot overlap the exit region.

In any of the prior embodiments, the eyepiece waveguide may be incorporated into an eyepiece for an augmented reality display system.

In any of the prior embodiments, the eyepiece may be configured to display a color image in multiple depth planes.

In any of the prior embodiments, the central beam of the set of input beams may be vertically incident on the ICG region.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is to receive a set of input beams of light, the set of input beams is associated with a set of k-vectors that form a field of view (FOV) shape in k-space, and the FOV shape is. The k-spatial ring has a first dimension in the k-space that is greater than the width of the k-spatial ring associated with the eyepiece waveguide, and the k-spatial ring is associated with the guided propagation within the eyepiece lens waveguide. Corresponding to regions in space, coupling them as guided beams into the substrate, and moving the FOV shape in parallel to both the first and second positions in the k-space ring. Thus, in the first position, part of the FOV shape is outside the k-space ring and only the first subpart of the FOV shape is the k-space ring. Inside, at the second position, part of the FOV shape is outside the k-space ring, and only the second subpart of the FOV shape is inside the k-space ring. The complete FOV shape is reassembled into the ICG region and the plurality of pupil expander regions formed on or within the substrate, the first and second subparts of the FOV shape. It comprises a plurality of pupil expander regions positioned to diffract the guided beam so as to move parallel to a third position in the k-spatial ring.

In a prior embodiment, the eyepiece waveguide further receives a beam diffracted by a plurality of pupil expander regions, which is an exit region formed on or within the substrate, and optically transmits them. There may be an exit region from the substrate that is externally coupled as a set of output beams that represents the complete set of input beams.

In any of the prior embodiments, at the first and second positions within the k-space ring, the first dimension of the FOV shape may extend radially in the k-space ring.

In any of the prior embodiments, at a third position within the k-space ring, the first dimension of the FOV shape may extend in the azimuth direction of the k-space ring.

In any of the prior embodiments, the FOV shape may have a second dimension in the k-space that is smaller than the width of the k-space ring, at first and second positions in the k-space ring. The second dimension of the FOV shape may extend in the azimuth direction of the k-space ring.

In any of the prior embodiments, at a third position within the k-space ring, the second dimension of the FOV shape may extend in the radial direction of the k-space ring.

In any of the prior embodiments, the FOV shape may comprise a FOV rectangle.

In any of the prior embodiments, the first and second subparts of the FOV shape cannot overlap.

In any of the prior embodiments, the first and second subparts of the FOV shape may overlap.

In any of the prior embodiments, the third position may be radially centered within the k-space ring.

In any of the prior embodiments, the central beam of the set of input beams may be vertically incident on the ICG region.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling lattice (ICG) region formed on or within the substrate. The ICG region is configured to receive a set of input beams of optics and combine the set of input beams into a substrate as a set of guided beams, where the set of input beams is a set of k-vectors in k-space. Associated with, the set of k-vectors has a first dimension in k-space that is greater than the width of the k-spatial ring associated with the eyepiece lens waveguide, and the k-spatial ring is the eyepiece guide. An ICG region corresponding to a region in k-space associated with guided propagation in a waveguide and a plurality of pupil expander regions formed on or within a substrate, collectively, ICG the guided beam. Multiple pupil expander regions that receive from the region and are positioned to diffract them to create a set of duplicate beams, and an exit region that is formed on or within the substrate and receives the duplicate beams. The duplicate beam is provided from an optically transmissive substrate with an exit region positioned to externally couple as a set of output beams representing a complete set of input beams.

式中、ｎ_２は、光学的に透過性の基板の屈折率であって、ｎ_１は、光学的に透過性の基板を囲繞する媒体の屈折率であって、ωは、光の入力ビームの角周波数であって、ｃは、光の速さの定数である、ＩＣＧ領域と、基板上または内に形成される、複数の瞳エクスパンダ領域であって、集合的に、ビームをＩＣＧ領域から受け取り、複製ビームのセットを作成するように、それらを回折するように位置付けられる、複数の瞳エクスパンダ領域と、基板上または内に形成される、出射領域であって、複製ビームを受け取り、複製ビームを、光学的に透過性の基板から、完全入力画像を表す、出力ビームのセットとして外部結合するように位置付けられる、出射領域とを備える。 In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate and an input coupling grating (ICG) region formed on or within the substrate. The ICG region comprises a diffraction grating configured to diffract a set of input beams of light corresponding to an input image to multiple diffraction orders, the grating having a period Λ that satisfies:

In the equation, n ₂ is the refractive index of the optically transmissive substrate, n ₁ is the refractive index of the medium surrounding the optically transmissive substrate, and ω is the input beam of light. The angular frequency of, c is the ICG region, which is a constant of the speed of light, and a plurality of pupil expander regions formed on or within the substrate, and collectively, the beam is in the ICG region. A plurality of optical expander regions that receive from and are positioned to diffract them to create a set of duplicate beams, and an exit region that is formed on or within the substrate and receives the duplicate beams. The duplicate beam is provided from an optically transmissive substrate with an exit region positioned to be externally coupled as a set of output beams representing a complete input image.

In the prior embodiments, the set of input beams may have an angular spread beyond the range of angles in the thickness direction of the optically transmissive substrate that can undergo total internal reflection in at least one direction. ..

In any of the prior embodiments, the angular spread of the set of input beams may be up to twice greater than the range of angles in the thickness direction of the optically transmissive substrate that may be subject to total internal reflection.

In any of the prior embodiments, the ICG region may be configured to diffract the input beam to a positive and negative diffraction order.

In any of the prior embodiments, the first pupil expander region may be positioned to receive an input beam diffracted to a positive diffraction order, and the second pupil expander region may have a negative diffraction order. It may be positioned to receive an input beam diffracted into.

In some embodiments, the eyepiece waveguide for an augmented reality display system is an optically transmissive substrate having a first surface and a second surface, and one of the surfaces of the substrate. A first input coupling lattice (ICG) region formed above or within, configured to receive an input beam of light and couple the input beam into a substrate as a guided beam. An ICG region and a multidirectional pupil expander (MPE) region formed on or within a first surface of a substrate, wherein the MPE region is at least a first periodic axis and a second periodic axis. With multiple diffraction features that exhibit periodicity along the MPE region, which is positioned to receive the guided beam from the first ICG region, diffract it in multiple directions, and create multiple diffracted beams. An exit pupil expander (EPE) region formed on or within a second surface of the substrate, the EPE region overlapping the MPE region and optically illuminating one or more of the diffracted beams. It is provided with an EPE region configured to be externally coupled as an output beam from a transmissive substrate.

In prior embodiments, the MPE and EPE regions may overlap at least 90%.

In any of the prior embodiments, the MPE region and the EPE region may be of the same size.

In any of the prior embodiments, the MPE region and the EPE region may be aligned with each other.

In any of the prior embodiments, the first ICG region may comprise a diffraction grating having a plurality of periodically repeating lines, the EPE region being the line of the diffraction grating within the first ICG region. It may include a diffraction grating having a plurality of periodically repeating lines that are vertically oriented.

In any of the prior embodiments, the MPE region may comprise a two-dimensional grid pattern with distinct diffraction features.

In any of the prior embodiments, the MPE region may include cross grids.

In any of the prior embodiments, the MPE region may be configured to create a diffracted beam by diffracting a portion of the power of the guided beam from the first ICG region in at least four directions.

In any of the prior embodiments, one of the four directions may correspond to a zero-order diffraction beam.

In any of the prior embodiments, three or more of the four directions may correspond to the primary diffraction beam.

In any of the prior embodiments, the four directions may be angularly separated by 90 degrees.

In any of the prior embodiments, the MPE region again diffracts the diffracted beam, which is still propagating within the MPE region after being initially diffracted, at multiple dispersal locations in the same direction. This may be configured to increase the number of diffracted beams.

In any of the prior embodiments, the first and second periodic axes in the diffraction feature of the MPE region cannot be orthogonal.

In any of the prior embodiments, the diffraction efficiency of the diffraction features in the MPE region may vary spatially.

In any of the prior embodiments, diffraction features located within the MPE region, closer to the first ICG region, may have higher diffraction efficiency.

In any of the prior embodiments, diffraction features located within the MPE region, along which the first ICG region is closer to the axis pointing the guided beam, may have higher diffraction efficiency.

In one of the prior embodiments, the eyepiece waveguide further comprises one or more additional ICG regions provided in one or more corresponding locations around the MPE region, with the MPE region at different locations. One or more corresponding additional light input beams incident on the lens may be provided.

In any of the prior embodiments, the diffraction efficiency of the diffraction features within the EPE region may vary spatially.

In any of the prior embodiments, diffraction features located closer to the periphery of the EPE region may have higher diffraction efficiency.

In any of the prior embodiments, the eyepiece waveguide may further include one or more diffractive mirrors located around the periphery of the substrate.

In any of the prior embodiments, the input beam may be collimated and have a diameter of 5 mm or less.

In any of the prior embodiments, the optically transmissive substrate may be flat.

In any of the prior embodiments, the eyepiece waveguide may be incorporated into an eyepiece for an augmented reality display system.

In any of the prior embodiments, the eyepiece may be configured to display a color image in multiple depth planes.

In any of the prior embodiments, the input beam may correspond to the center of the input image and be vertically incident on the ICG region.

In any of the prior embodiments, the first ICG region may be configured to receive a set of input beams of a plurality of lights, the set of input beams having a field of view (FOV) shape in k-space. Associated with the set of k-vectors to form, the FOV shape has a first dimension in the k-space that is greater than the width of the k-space ring associated with the eyepiece waveguide, and the k-space ring. Corresponds to the regions in k-space associated with guided propagation within the eyepiece lens waveguide, the first ICG region to couple them as guided beams into the substrate, and the FOV shape. The FOV shape may be configured to diffract the input beam so that it moves parallel to a first position that is completely within the k-space ring.

In any of the prior embodiments, at the first position in the k-space ring, the first dimension of the FOV shape may extend in the azimuth direction of the k-space ring.

In any of the prior embodiments, the MPE region diffracts the guided beam from the first ICG region so that the FOV shape is translated into both the second and third positions within the k-space ring. In a second position, part of the FOV shape is outside the k-space ring and only the first subpart of the FOV shape is inside the k-space ring. At the third position, part of the FOV shape is outside the k-space ring and only the second subpart of the FOV shape is inside the k-space ring.

In any of the prior embodiments, at the second and third positions within the k-space ring, the first dimension of the FOV shape may extend in the radial direction of the k-space ring.

In any of the prior embodiments, the EPE region is a central position in k-space in which the first subpart of the FOV shape is surrounded by the k-space ring from a second position in the k-space ring. The diffracted beam from the MPE region is further diffracted so that the second subpart of the FOV shape is translated from the third position in the k-space ring to the center position. May be done.

In any of the prior embodiments, the complete FOV shape may be reassembled at the center position.

In any of the prior embodiments, the first and second subparts of the FOV shape cannot overlap.

In any of the prior embodiments, the first and second subparts of the FOV shape may overlap.

In any of the prior embodiments, the eyepiece waveguide may provide a field of view with a magnitude of 60 degrees in the first dimensional direction of the FOV shape.

In any of the prior embodiments, the central beam of the set of input beams may be vertically incident on the ICG region.

In any of the prior embodiments, the first ICG region may be located above the MPE region and the EPE region when the eyepiece waveguide is in the mounted orientation.

In any of the prior embodiments, the eyepiece waveguide may further comprise a second ICG region, the MPE region and the EPE region located between the first ICG region and the second ICG region. do.

In any of the prior embodiments, the first ICG region may be located on the nasal side of the MPE region and the EPE region and the second ICG region may be located when the eyepiece waveguide is in the mounting orientation. It may be located on the temple side of the MPE region and the EPE region.

In any of the prior embodiments, both the first ICG region and the second ICG region may comprise a diffraction grating having a plurality of periodically repeating lines extending in the same direction.

In any of the prior embodiments, the EPE region may comprise a diffraction grating having a plurality of periodically repeating lines oriented perpendicular to the lines of the diffraction grating in the first and second ICG regions. ..

In any of the prior embodiments, the eyepiece waveguide may be configured to receive a set of input beams that form the input image, the set of input beams being the field of view (FOV) in k-space. Associated with the set of k-vectors that form the shape, the FOV shape has a first dimension in the k-space that is greater than the width of the k-space ring associated with the eyepiece waveguide and k-. The spatial ring corresponds to the region in the k-space associated with the guided propagation in the eyepiece waveguide, and the first ICG region couples them into the substrate as a guided beam and has a FOV shape. A first subset of the input beam corresponding to the first subpart of the FOV shape so that the first subpart of the FOV shape is moved parallel to the first position where the first subpart of the FOV shape is completely within the k-spatial ring. The second ICG region may be configured to receive and diffract a first subset of the input beam so that they are coupled into the substrate as a guided beam and the FOV shape is FOV shape. The input beam receives a second subset of the input beam corresponding to the second subpart of the FOV shape so that the second subpart is moved parallel to the second position, which is completely within the k-spatial ring. It may be configured to diffract a second subset of.

In any of the prior embodiments, the MPE region translates the first subpart of the FOV shape into both the third and fourth positions within the k-space ring. The MPE region may be configured to diffract the guided beam from, further translating the second subpart of the FOV shape to both the third and fourth positions within the k-space ring. As such, it may be configured to diffract the guided beam from the second ICG region.

In any of the prior embodiments, at the third and fourth positions within the k-space ring, the first dimension of the FOV shape may extend in the azimuth direction of the k-space ring.

In any of the prior embodiments, the complete FOV shape may be reassembled in the third and fourth positions.

In any of the prior embodiments, the first and second subparts of the FOV shape cannot overlap.

In any of the prior embodiments, the first and second subparts of the FOV shape may overlap.

In one of the prior embodiments, the EPE region encloses the fully reassembled FOV shape by the k-space ring from both the third and fourth positions within the k-space ring, k-. It may be configured to further diffract the diffracted beam from the MPE region so that it is translated into a central position in space.

In any of the prior embodiments, the eyepiece waveguide may provide a field of view with a magnitude of 100 degrees in the first dimensional direction of the FOV shape.

In any of the prior embodiments, a first instance of the eyepiece waveguide and a second instance of the eyepiece waveguide may be provided in a binocular configuration.

In any of the prior embodiments, the field of view of the first instance of the eyepiece waveguide may overlap with the field of view of the second instance of the eyepiece waveguide.

In any of the prior embodiments, the binocular configuration may provide a field of view in one direction of 150 degrees or greater.

In any of the prior embodiments, the eyepiece waveguide further comprises a first pair of orthogonal pupil expander (OPE) regions opposite the first ICG region and a second opposite side of the second ICG region. It may have two pairs of OPE regions.

In any of the prior embodiments, both the first ICG region and the second ICG region may comprise a diffraction grating having a plurality of periodically repeating lines extending in the same direction.

In any of the prior embodiments, the EPE region may comprise a diffraction grating having a plurality of periodically repeating lines oriented in the same direction as the diffraction grating lines in the first and second ICG regions. good.

In any of the prior embodiments, the eyepiece waveguide may be configured to receive a set of input beams that form the input image, the set of input beams being the field of view (FOV) in k-space. Associated with the set of k-vectors that form the shape, the FOV shape has first and second dimensions in the k-space that are greater than the width of the k-space ring associated with the eyepiece waveguide. , The k-spatial ring corresponds to the regions in the k-space associated with the guided propagation in the eyepiece lens waveguide, and the first ICG region couples at least a portion of them as a guided beam into the substrate. And to move the FOV shape in parallel to the first and second positions where at least the first and second subparts of the FOV shape are completely within the k-spatial ring, respectively. The second ICG region may be configured to diffract the set so that at least a portion of them is coupled into the substrate as a guided beam and the FOV shape is at least the first and first of the FOV shape. The two subparts may be configured to diffract a set of input beams so that they move parallel to the first and second positions, respectively, completely within the k-spatial ring.

In any of the prior embodiments, the first pair of OPE regions has the first and second subparts of the FOV shape, and at least the first part of the first and second subparts of the FOV shape is k-. The guided beam from the first ICG region may be configured to diffract the guided beam from the first ICG region so that it translates into a third position that is completely within the space ring, and the second pair of OPE regions has a FOV shape. The first and second subparts of the FOV shape are translated into a fourth position where at least the second part of the first and second subparts of the FOV shape is completely within the k-space ring. It may be configured to diffract the guided beam from the second ICG region.

In any of the prior embodiments, the MPE region translates the first portion of the first and second subparts of the FOV shape into the first, second, and fourth positions within the k-space ring. The MPE region may be configured to diffract the guided beam from the first pair of OPE regions so that the second portion of the first and second subparts of the FOV shape is k-. It may be configured to further diffract the guided beam from the second pair of OPE regions so that it translates to the first, second, and third positions in the space ring.

In one of the prior embodiments, the EPE region is to further diffract the diffracted beam from the MPE region so that the complete FOV shape is reassembled into a central position in the k-space surrounded by the k-space ring. It may be configured in.

In any of the prior embodiments, the first and second subparts of the FOV shape cannot overlap.

In any of the prior embodiments, the first and second subparts of the FOV shape may overlap.

In any of the prior embodiments, the central beam of the set of input beams may be vertically incident on the first ICG region and the second ICG region.

(Additional considerations)
Throughout the description and claims, unless otherwise explicitly required by the context, the words "prepared", "equipped with", "contains", "contains", "has" , "Having" and equivalents should be construed in an inclusive sense, i.e., "including, but not limited to," as opposed to an exclusive or inclusive meaning. .. The word "combined" can be either directly connected or connected via one or more intermediate elements, as is commonly used herein. Refers to the element of. Similarly, the word "connected" can be either directly connected or connected via one or more intermediate elements, as is commonly used herein. Refers to two or more elements. Depending on the context, "coupled" or "connected" can refer to an optical coupling or optical connection such that light is coupled or connected from one optical element to another. In addition, the words "in the present specification", "above", "below", "described below", "described above", and words of similar meaning, as used herein, refer to the present application as a whole. However, it does not refer to any particular part of the present application. Where permitted by the context, the words in the above detailed description using the singular or plural may also include the plural or singular, respectively. The word "or" is an inclusive (not exclusive) "or" when referring to a list of two or more items, and the "or" is the entire interpretation of the following words, i.e., within the list. Covers any combination of any of the items in the list, all of the items in the list, and any combination of one or more of the items in the list, and does not exclude other items added to the list. In addition, the articles "a", "an", and "the", when used in this application and the accompanying claims, may be "one or more" or "at least one" unless otherwise specified. Should be interpreted as meaning.

As used herein, the phrase referring to the list of items "at least one of" refers to any combination of those items, including a single element. As an example, "at least one of A, B, or C" covers A, B, C, A and B, A and C, B and C, and A, B, and C. Is intended. Contextual statements such as the phrase "at least one of X, Y, and Z" generally have an item, term, etc. of at least one of X, Y, or Z, unless specifically stated otherwise. It is understood differently in the context as it is used to convey what can be. Therefore, such a connection statement generally suggests that an embodiment requires that at least one of X, at least one of Y, and at least one of Z be present, respectively. Not intended to be.

Furthermore, in particular, "can", "could", "might", "may", "eg (eg)", " Conditional statements used herein, such as, for example, "such as", and equivalents, are used unless otherwise specified or in the context in which they are used. Unless otherwise understood, it should be understood that, in general, it is intended to convey that some embodiments contain certain features, elements, and / or conditions, while other embodiments do not. Thus, such conditional statements are generally such that features, elements, and / or states are required for one or more embodiments, or these features, elements, and / or states. Is not intended to suggest whether is included or should be implemented in any particular embodiment.

Although certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Any one feature of the embodiment can be combined with and / or substituted for any other one feature of the embodiment. Certain advantages of various embodiments have been described herein. However, not all embodiments necessarily achieve each of these advantages.

The embodiments have been described in connection with the accompanying drawings. However, the figure is not drawn to the exact scale. Distances, angles, etc. are merely exemplary and do not necessarily convey an exact relationship to the actual dimensions and layout of the illustrated device.

The aforementioned embodiments have been described in some detail to allow one of ordinary skill in the art to make and use the devices, systems, methods and the like described herein. Various variants are possible. Components, elements, and / or steps may be modified, added, removed, or rearranged. Although one embodiment has been explicitly described, other embodiments will also be apparent to those of skill in the art based on the present disclosure.

Claims (37)

An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling lattice (ICG) region formed on or within the substrate, wherein the ICG region is.
Receiving a set of input beams of light, said set of input beams is associated with a set of k-vectors in k-space.
By diffracting the set of input beams so as to create a set of first guided beams and a set of first non-diffracted beams, the first set of guided beams is the eyepiece waveguide. Corresponding to the parallel movement subset of the k-vector within the k-space ring associated with the tube, the first set of non-diffraction beams is of the k-vector outside the k-space ring. Corresponding to the parallel movement subset, the k-space ring corresponds to the region in k-space associated with the guided propagation in the eyepiece lens waveguide.
By diffracting the set of input beams so as to create a separate set of second guided beams and a separate set of second non-diffracted beams, the second set of guided beams is said to be said. The second set of non-diffraction beams corresponds to the translation subset of the k-vector inside the k-space ring and corresponds to the translation subset of the k-vector outside the k-space ring. To do
The ICG area, which is configured to do
A first pupil expander region formed on or within the substrate, wherein the first pupil expander region is positioned to receive the set of the first guided beams from the ICG region and they. With a first pupil expander region configured to replicate as a set of first replica beams,
A second pupil expander region formed on or within the substrate, wherein the second pupil expander region is positioned to receive the set of the second guided beam from the ICG region and they. With a second pupil expander region configured to replicate as a set of second replication beams,
An exit region formed on or within the substrate, the exit region is positioned to receive a set of the first and second replicated beams, the exit region externally coupled with them as an output beam. The output beam is configured to represent a complete set of input beams with an exit region.
Equipped with an eyepiece waveguide. The eyepiece waveguide according to claim 1, wherein the first set of guided beams corresponds to a positive diffraction order in the ICG region, and the second set of guided beams corresponds to a negative diffraction order. tube. The translational subset of the k-vector associated with the first set of guided beams is located at a first position within the k-space ring and is associated with the second set of guided beams. The eyepiece waveguide according to claim 1, wherein the translational subset of the k-vector is located at a second position in the k-space ring opposite to the first position. The eyepiece waveguide according to claim 3, wherein the center points of the first and second positions are separated by 180 degrees. The first pupil expander region and the second pupil expander region are associated with a subset of the k-vectors associated with the first set of guided beams and the second set of guided beams, respectively. The eyepiece waveguide according to claim 1, wherein the obtained subset of the k-vector is translated into adjacent positions in the k-space ring. 5. The first set of guided beams and the second set of guided beams each individually represent only a subset of the input beams, but collectively represent the complete set of the input beams, claim 5. The eyepiece waveguide described. The first pupil expander region and the second pupil expander region are associated with a subset of the k-vectors associated with the first set of guided beams and the second set of guided beams, respectively. The eyepiece waveguide according to claim 1, wherein the resulting subset of the k-vectors are translated into overlapping positions in the k-space ring. 7. The first set of guided beams and the second set of guided beams each individually represent only a subset of the input beams, but collectively represent the complete set of the input beams, claim 7. The eyepiece waveguide described. The eyepiece waveguide according to claim 1, wherein the set of k-vectors associated with the set of input beams has a first dimension in k-space that is greater than the width of the k-space ring. .. The eyepiece waveguide according to claim 9, wherein the first dimension is up to twice the width of the k-space ring. The eyepiece waveguide according to claim 9, wherein the first dimension corresponds to a field of view of at least 60 degrees. The eyepiece waveguide according to claim 9, wherein the set of k-vectors associated with the set of input beams has a second dimension not greater than the width of the k-space ring. The eyepiece waveguide according to claim 9, wherein the set of input beams is associated with an input image. The eyepiece waveguide according to claim 1, wherein the first and second pupil expander regions include an orthogonal pupil expander (OPE) region. The eyepiece waveguide according to claim 1, wherein the exit region includes an exit pupil expander (EPE) region. The eyepiece waveguide according to claim 1, wherein each of the input beams is collimated and has a diameter of 5 mm or less. The eyepiece waveguide according to claim 1, wherein the first and second pupil expander regions do not overlap with the emission region. The eyepiece waveguide according to claim 1, wherein the eyepiece waveguide is incorporated into an eyepiece for an augmented reality display system. The eyepiece waveguide according to claim 18, wherein the eyepiece is configured to display a color image on a plurality of depth planes. The eyepiece waveguide according to claim 1, wherein the central beam of the set of input beams is vertically incident on the ICG region. An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling lattice (ICG) region formed on or within the substrate, wherein the ICG region is.
Receiving a set of input beams of light, said set of input beams is associated with a set of k-vectors forming a field of view (FOV) shape in k-space, said FOV shape is said eyepiece. Having a first dimension in k-space that is greater than the width of the k-space ring associated with the lens waveguide, said k-space ring was associated with guided propagation within the eyepiece lens waveguide. Corresponding to the area in k-space,
The input beam is coupled into the substrate as a guided beam and the FOV shape is translated into both the first and second positions in the k-space ring. At the first position, part of the FOV shape is outside the k-space ring, and only the first subpart of the FOV shape is inside the k-space ring. At the second position, a part of the FOV shape is outside the k-space ring, and only a second subpart of the FOV shape is inside the k-space ring.
The ICG area, which is configured to do
A plurality of pupil expander regions formed on or within the substrate, wherein the first and second sub-parts of the FOV shape are completely reassembled into the FOV shape. With a plurality of pupil expander regions positioned to diffract the guided beam so as to translate to a third position in the k-space ring.
Equipped with an eyepiece waveguide. It further comprises an exit region formed on or within the substrate, which receives the beams diffracted by the plurality of pupil expander regions and delivers them from the optically transmissive substrate. 21. The eyepiece waveguide according to claim 21, which is positioned to be externally coupled as a set of output beams representing a complete set of input beams. 21. The eyepiece guide according to claim 21, wherein at the first and second positions within the k-space ring, the first dimension of the FOV shape extends in the radial direction of the k-space ring. Waveguide. 23. The eyepiece waveguide according to claim 23, wherein at the third position in the k-space ring, the first dimension of the FOV shape extends in the azimuth direction of the k-space ring. .. The FOV shape has a second dimension in the k-space that is smaller than the width of the k-space ring, and at the first and second positions in the k-space ring, the FOV shape said. The eyepiece waveguide according to claim 21, wherein the second dimension extends in the azimuth direction of the k-space ring. 25. The eyepiece waveguide according to claim 25, wherein at the third position within the k-space ring, the second dimension of the FOV shape extends in the radial direction of the k-space ring. The eyepiece waveguide according to claim 21, wherein the FOV shape includes a FOV rectangle. The eyepiece waveguide according to claim 21, wherein the first and second sub-parts of the FOV shape do not overlap. The eyepiece waveguide according to claim 21, wherein the first and second sub-parts of the FOV shape overlap. 21. The eyepiece waveguide according to claim 21, wherein the third position is centered radially within the k-space ring. 21. The eyepiece waveguide according to claim 21, wherein the central beam of the set of input beams is vertically incident on the ICG region. The eyepiece waveguide for the augmented reality display system.
With an optically transparent substrate,
An input coupled lattice (ICG) region formed on or within the substrate, the ICG region receiving a set of input beams of light and using the set of input beams as a set of guided beams in the substrate. Configured to combine, the set of input beams is associated with a set of k-vectors in k-space, and the set of k-vectors is associated with the eyepiece lens waveguide. The k-space ring has a first dimension in k-space that is greater than the width of the ICG region, the k-space ring corresponding to the region in k-space associated with guided propagation within the eyepiece lens waveguide. When,
A plurality of pupil expander regions formed on or within the substrate, wherein the plurality of pupil expander regions collectively receive the guided beam from the ICG region to create a set of duplicate beams. With multiple pupil expander regions, positioned to diffract them,
An exit region formed on or within the substrate, which receives the replica beam and outputs the replica beam from the optically transmissive substrate to represent a complete set of input beams. With the exit region, which is positioned to externally couple as a set of beams
Equipped with an eyepiece waveguide. An eyepiece waveguide for an augmented reality display system, wherein the eyepiece waveguide is:
With an optically transparent substrate,
An input coupling grating (ICG) region formed on or within the substrate, wherein the ICG region is configured to diffract a set of input beams of light corresponding to an input image to a plurality of diffraction orders. The diffraction grating is provided, and the diffraction grating is

Has a period Λ that satisfies, n ₂ Is the refractive index of the optically transmissive substrate, and is n ₁ Is the refractive index of the medium surrounding the optically transmissive substrate, ω is the angular frequency of the input beam of the light, and c is the constant of the speed of light in the ICG region.
A plurality of pupil expander regions formed on or within a substrate, wherein the plurality of pupil expander regions collectively receive the beam from the ICG region and create a set of duplicate beams. Multiple pupil expander regions, positioned to diffract them,
An exit region formed on or within the substrate, which receives the duplicate beam and transfers the duplicate beam from the optically transmissive substrate to a set of output beams representing a complete input image. With the exit region, which is positioned to outerly bond as
Equipped with an eyepiece waveguide. 33. The set of input beams has an angular spread beyond the range of angles in the thickness direction of the optically transmissive substrate that can undergo total internal reflection in at least one direction. Eyepiece waveguide. 34. The eyepiece guide according to claim 34, wherein the angular spread of the set of input beams exceeds the range of the angle in the thickness direction of the optically transmissive substrate, which is capable of receiving total internal reflection. Waveguide. The eyepiece waveguide according to claim 33, wherein the ICG region is configured to diffract the input beam to a positive diffraction order and a negative diffraction order. The first pupil expander region is positioned to receive the input beam diffracted to the positive diffraction order, and the second pupil expander region receives the input beam diffracted to the negative diffraction order. 36. The eyepiece waveguide according to claim 36, which is positioned to receive.

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